TWI610614B - Flexible flat cable - Google Patents

Abstract

A mask film that can be easily grounded without exposing the ground conductor of the substrate to which the mask film is attached, and a mask wiring board that can use the mask film and has a mask function and an impedance control function in one step , And the grounding method using the mask film. The masking film (20) connected to the conductive member (30) by heating and pressing is formed of a resin having a melting point higher than the temperature at the time of heating. The masking film (20) includes: a cover film (25), At the time of connection, a layer thickness (L1) that is thinner than the average protrusion length (L2) of the conductive particles (35) protruding from the conductive adhesive layer (33); and the metal sequentially stacked on the cover film (25) Thin film layer (24) and adhesive layer (23).

Description

Flexible flat cable

The present invention relates to a shield film used in a substrate with a conductive body such as a flexible flat cable, a shield wiring board having the shield film, and a ground of the shield film )connection method.

Conventionally, substrates with conductors such as flexible flat cables have been used in various electronic devices such as office automation (OA) equipment represented by televisions, video recorders, mobile phones, and personal computers. Used to connect devices inside or between devices.

In addition, in recent years, due to the development of the information society, electronic devices have been required to increase the speed of electronic communications. In order to reduce unnecessary radiation from high-speed electrical signals or noise from the outside, flexible and flat A masking film is attached to a substrate having a conductor such as a cable. Furthermore, because impedance matching with the connected device is required, the substrate is attached with an impedance control film having a function of controlling the impedance.

For example, in Patent Document 1, as shown in FIG. 6, a flexible flat cable 50 is disclosed, in which a plurality of conductors including a signal conductor 51 and a ground conductor 52 are arranged side by side in the width direction, and consist of an insulating adhesive layer 53 The foamed insulator 54 in the thickness direction, after sandwiching the plurality of conductors from both sides, undergoes a lamination process, and then is sandwiched from both sides by a metal layer 56 having a conductive adhesive layer 55 Foam insulator 54. In addition, an insulating film 57 is provided on the metal layer 56.

The flexible flat cable 50 having the above-described configuration can adjust the characteristic impedance by combining the dielectric constant of the foam insulator 54 and the dielectric constant of air. In addition, the flexible flat cable 50 has a shielding effect under the action of the metal layer 56.

In addition, for example, in Patent Document 2, as shown in FIG. 7, an impedance control mask wiring board 60 is disclosed in which a plurality of conductors including a signal conductor 61 and a ground conductor 62 are arranged side by side on a base film 63 Arranged in the width direction and provided with an insulating layer 64, and in turn, an impedance control film including an opening metal thin film layer 66 having a conductive adhesive layer 65 and an insulating film 67, and a conductive adhesive layer 68 The non-opening metal thin film layer 69 and the insulating film 70 are masking films.

The impedance control mask wiring board 60 having the above-mentioned configuration has an impedance control effect under the action of the opening metal thin film layer 66, and has a mask effect under the action of the non-opening metal thin film layer 69.

[Advanced technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-31033

[Patent Document 2] Japanese Patent Laid-Open No. 2006-24824

However, as shown in FIG. 6, for the flexible flat cable 50 of Patent Document 1, in order to set the potential of the metal layer 56 to the ground potential, the conductive adhesive layer 55, the foam insulator 54, and the adhesive layer 53 need to be specifically prepared in advance. A non-insulating portion 58 is formed on a part of the inside, and the metal layer 56 and the ground conductor 52 are connected by filling the conductive adhesive layer 59 of the non-insulating portion 58.

In addition, in order to obtain the two effects of the impedance effect and the shielding effect of the flexible flat cable 50, at least two steps, namely, the step of processing the foamed insulator 54 and the step of clamping the metal layer 56 are required.

In addition, as shown in FIG. 7, in the impedance control mask wiring board 60 of Patent Document 2, in order to make the potential of the opening metal thin film layer 66 the ground potential, it is also necessary to intentionally provide a part of the insulating layer 64 in advance. The insulating portion 71 connects the opening metal thin film layer 66 and the ground conductor 62 by filling the conductive adhesive layer 65 of the non-insulating portion 71.

In addition, in order for the impedance control mask wiring board 60 to obtain both the impedance effect and the mask effect, at least two steps of forming the two layers of the opening metal thin film layer and the non-opening metal thin film layer are required.

In this way, the flexible flat cable 50 of Patent Document 1 and the impedance control shield wiring board 60 of Patent Document 2 have the following problem: In order to obtain the shielding effect and the impedance control effect, it is necessary to specifically provide a non-insulating portion and expose the ground conductor, or At least two steps are required to form a layer with a masking effect and a layer with an impedance control effect, which takes time and cost.

Therefore, an object of the present invention is to provide a mask film that can be easily grounded without exposing the ground conductor of the substrate to which the mask film is attached, and can use the mask film to have a mask function and impedance in one step Shield wiring board for control function, and grounding method using the shielding film.

The mask film of the present invention is connected to a conductive member by heating and pressing, the conductive member including a metal layer for connecting to an external ground member in a contact state and a conductive adhesive layer containing conductive particles, the mask The cover film includes a cover film formed of a resin softened by the heating, and after being connected by the heating and pressurization, the conductive film protrudes from the conductive adhesive layer. The average protruding length of the sex particles is a thinner layer thickness, followed by the conductive adhesive layer; and the metal thin film layer and the adhesive layer sequentially stacked on the cover film.

According to the above configuration, when the conductive member is connected to the mask film including the cover film, the metal thin film layer, and the adhesive layer by heating and pressurization, the cover film formed of resin in the mask film is heated by It softens, and at the time of connection, the layer thickness of the cover film is thinner than the average protruding length of the conductive particles protruding from the conductive adhesive layer in the conductive member, therefore, the conductive particles protruding from the conductive adhesive layer due to pressure It can penetrate the cover film in the mask film and reach the metal thin film layer. Thereby, since the potential of the metal thin film layer in the mask film can be grounded via conductive particles, there is no need to connect the ground conductor in the substrate to which the mask film is attached to the metal in the mask film as in the past The thin film layer is connected. Therefore, there is no need to process the substrate in advance to expose the ground conductor, and no processing cost is consumed. In addition, since only the conductive member is connected to the mask film, even when, for example, a long substrate is used, the mask film can be easily grounded at a desired position.

In addition, in the mask film of the present invention, an interposer layer may be further adhered to the adhesive layer, and by adhering the interposer layer to a substrate having a conductor, the impedance of the substrate having the conductor may be control.

According to the above configuration, by adjusting the thickness of the insertion layer, the impedance of the substrate having the conductor can be adjusted. Therefore, the mask film includes a layer that adjusts the impedance of the substrate with a conductor and a layer with a masking effect, and the masking effect can be imparted to the substrate by only one step of attaching the masking film to the substrate In addition, the substrate can be given an impedance control effect.

In addition, in the mask film of the present invention, the substrate may be a flexible flat cable.

According to the above configuration, it is possible to provide a masking film attached to the flexible flat cable.

In addition, the present invention is a mask wiring board including a substrate having a conductor and the mask film as described above.

According to the above configuration, the mask wiring board to which the mask film is attached can be provided.

In addition, the present invention is a grounding method for a masking film. The masking film includes a cover film formed of a resin, and a metal thin film layer and an adhesive layer sequentially stacked on the cover film. The characteristics are:

The conductive member includes a metal layer connected to an external ground member in a contact state and a conductive adhesive layer containing conductive particles, and the conductive member is heated and pressurized at a temperature at which the resin softens to increase the conductivity The subsequent layer and the cover film are adhered, whereby the conductive particles protruding longer than the layer thickness of the cover film reach the metal thin film layer to be grounded.

According to the grounding method, when the conductive member is connected to the mask film including the cover film, the metal thin film layer, and the adhesive layer by heating and pressing, the cover film formed of resin in the mask film is heated by It softens, and when connected, the layer thickness of the cover film is thinner than the average protruding length of the conductive particles protruding from the conductive adhesive layer in the conductive member. Therefore, the conductivity of the conductive particles protruding from the conductive adhesive layer due to pressure The particles can penetrate the cover film in the mask film and reach the metal thin film layer. Thereby, since the potential of the metal thin film layer in the mask film can be grounded via conductive particles, there is no need to connect the ground conductor in the substrate to which the mask film is attached to the metal in the mask film as in the past The thin film layer is connected. Therefore, there is no need to process the substrate in advance to expose the ground conductor, and no processing cost is consumed. In addition, since only the conductive member is connected to the mask film, even when, for example, a long substrate is used, the mask film can be easily grounded at a desired position.

[Effect of invention]

According to the mask film of the present invention, since the potential of the metal thin film layer in the mask film can be grounded via conductive particles, there is no need to process the substrate in advance to expose the ground conductor. Consume processing costs. In addition, since only the conductive member is connected to the mask film, the mask film can be easily grounded at a desired position.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and can be implemented according to the content of the specification, the following is a detailed description of the preferred embodiments of the present invention and the accompanying drawings.

Hereinafter, embodiments of the present invention will be described based on the drawings.

(Overall composition)

As shown in FIG. 1, the mask film 20 of the present invention is connected to a conductive member 30 by heating and pressing. The conductive member 30 includes a metal layer for connecting to an external ground member in a contact state and contains conductive particles 35. The conductive adhesive layer 33. The mask film 20 includes a cover film 25 formed of a resin softened by heating. When connected by heating and pressurization, it is formed from the conductive adhesive layer 33. The protruding conductive particles 35 have a thinner layer thickness L1 with an average protruding length L2, and are next to the conductive adhesive layer 33; and the metal thin film layer 24 and the adhesive layer 23 that are sequentially stacked on the cover film 25.

In addition, as shown in FIG. 1, the mask film 20 of the present invention is attached to a substrate having a conductor such as a flexible flat cable 10, and the mask film 20 has the following functions: reducing excess radiation from electrical signals or from External noise and adjust the impedance so that there is no impedance mismatch between the flexible flat cable 10 and the equipment connected to the flexible flat cable 10.

In addition, since the mask film 20 of the present invention is connected to the conductive member 30 connected to the external ground member by heating and pressurization, the potential of the mask film 20 can be set to the ground potential.

Here, the “connection” means that at least two members are electrically connected at least. In this case, the “connection” means that the mask film 20 and the conductive member 30 are electrically connected at least.

(Conductive member 30)

Here, first, the conductive member 30 connected to the mask film 20 of the present invention will be described. As shown in FIGS. 4 (a) and 4 (b), the conductive member 30 has a structure in which a gold plating is applied to the metal layer 32 that is in contact with the conductive adhesive layer 33 including the conductive particles 35. Plating layer 31 such as a layer, a tin plating layer, or the like.

(Conductive adhesive layer 33)

The conductive adhesive layer 33 contained in the conductive member 30 is formed as a mixture of the conductive particles 35 and the adhesive 34 (acrylic resin or the like). That is, the conductive adhesive layer 33 is formed by dispersing the conductive particles 35 in the adhesive 34 such as acrylic resin. The electrical connection of the conductive adhesive layer 33 is achieved by the continuous contact of one or more conductive particles 35 in the adhesive 34 in the thickness direction of the conductive adhesive layer 33 and the adhesion of the adhesive 34 To maintain.

(Adhesive 34)

Examples of the adhesive 34 contained in the conductive adhesive layer 33 include acrylic resins, epoxy resins, silicon resins, thermoplastic elastomer (elastomer) resins, and gum resins. , And polyester resins. Furthermore, the adhesive 34 may be a monomer of the resin or a mixture of the resin.

In addition, the adhesive 34 may further contain a tackifier. Examples of tackifiers include fatty acid hydrocarbon resins, C5 / C9 mixed resins, rosin, rosin derivatives, special resins, terpene resins, aromatic hydrocarbon resins, and heat-reactive resins. Tackifier.

(Conductive particles 35)

A part or all of the conductive particles 35 included in the conductive adhesive layer 33 are formed by a metal material. For example, the conductive particles 35 include copper powder, silver powder, nickel powder, copper powder covered with silver (Cu powder covered with Ag), copper powder covered with gold, nickel powder covered with silver (covered with Ag Ni powder), and nickel powder covered with gold, these metal powders can be produced by a water atomization method, a carbonyl method, or the like. In addition to the powder, particles coated with resin on metal powder and particles coated with metal powder on resin can also be used. Furthermore, the conductive particles 35 are preferably Cu powder covered with Ag or Ni powder covered with Ag. The reason is that the conductive particles 35 with improved conductivity can be obtained by an inexpensive material.

As shown in FIG. 4 (a), the conductive particles 35 are in contact with the metal layer 32, and part of the conductive particles 35 are separated from the conductive adhesive layer 33 on the side attached to the mask film 20. protruding.

(Metal layer 32)

The metal layer 32 contained in the conductive member 30 is made of nickel, copper, silver, tin, gold, palladium, aluminum, chrome, titanium, zinc, and those containing these materials It is formed of a metal material such as any one material or an alloy of two or more materials.

In addition, as shown in FIG. 2, the metal layer 32 is connected to an external ground member such as a housing, and the potential of the metal layer 32 is maintained at the ground potential.

Furthermore, a plating layer 31 such as a gold plating layer, a tin plating layer, or the like is applied on the metal layer 32.

(Mask film 20)

As shown in FIG. 1, the mask film 20 of the present invention using the conductive member 30 to be grounded is sequentially laminated in a layered manner with an insertion layer 22 having an adhesive layer 21, a metal thin film layer 24 having an adhesive layer 23, and a cover膜 25。 Film 25.

(Cover 25)

The cover film 25 included in the mask film 20 is formed of epoxy-based, polyester-based, acrylic-based, phenol-based, urethane-based resin, or a mixture of these resins.

Here, the round portion E in FIG. 1 is an enlarged portion when the conductive adhesive layer 33 in the conductive member 30 is adhered to the cover film 25.

As shown in the circle E of FIG. 1, when the conductive member 30 is connected to the mask film 20, the conductive adhesive layer 33 in the conductive member 30 is connected to the cover film 25 in the mask film 20. When this bonding is achieved, the cover film 25 is heated from the conductive member 30 side and softened.

The epoxy resin forming the cover film 25 is formed of a resin softened at a heating temperature when the conductive member 30 is connected to the mask film 20, and the softening temperature of the resin is in the range of 100 ° C to 140 ° C.

In addition, as shown in the circle E of FIG. 1, the conductive particles 35 exist inside the conductive adhesive layer 33 in the conductive member 30. When the mask film 20 and the conductive member 30 are connected, a part of the conductive particles 35 protrudes from the conductive adhesive layer 33, and the average protruding length L2 of the conductive particles 35 of the protruding portion is set to be The layer thickness L1 is longer.

(Metal film layer 24)

The metal thin film layer 24 contained in the masking film 20 has a masking effect that reduces unnecessary radiation from electrical signals or noise from the outside.

In addition, since the conductive member 30 connected to the external ground member is connected to the mask film 20 by heating and pressing, the metal thin film layer 24 passes through the conductive particles 35 in the conductive adhesive layer 33 of the cover film 25 Connected to the conductive member 30. Thereby, the shielding film 20 can be grounded through the conductive member 30.

Examples of the metal material forming the metal thin film layer 24 include nickel, copper, silver, tin, gold, palladium, aluminum, chromium, titanium, zinc, and alloys containing any one or two or more of these materials Wait. In addition, the metal material and thickness of the metal thin film layer 24 may be appropriately selected according to the required mask effect, repeated bending resistance, and sliding resistance, but the thickness is set to a thickness of about 3 μm to 20 μm That's it. In addition, it is preferably 6 μm to 15 μm, and more preferably 9 μm to 12 μm. If the thickness is less than 3 μm, sufficient transmission characteristics cannot be obtained, and if the thickness exceeds 20 μm, bendability becomes a problem. In addition, the metal thin film layer 24 may be a metal foil, a plating layer, or the like, but it is preferably a metal foil.

(Insert layer 22)

The insertion layer 22 contained in the mask film 20 is made of polyethylene terephthalate (polyethylene terephthalate), polyethylene (polyethylene), polypropylene (polypropylene), expanded polyethylene terephthalate, It is composed of foamed polyethylene, foamed polypropylene, non-woven fabric, and the like, and is laminated on the metal thin film layer 24 by the adhesive layer 23, thereby further increasing the thickness of the mask film 20. In addition, by adjusting the thickness, when the mask film 20 is attached to the flexible flat cable 10, the impedance of the flexible flat cable 10 can be adjusted. Furthermore, the insertion layer 22 can be adhered to the flexible flat cable 10 by the adhesion layer 21. According to such a configuration, the masking film 20 can adhere the insertion layer 22 to the flexible flat cable 10 or the like by the adhesion layer 23. In this way, by adjusting the thickness of the insertion layer 22, the impedance of the flexible flat cable 10 can be adjusted. Therefore, the masking film 20 includes a layer for adjusting the impedance of the flexible flat cable 10 and a layer having a masking effect. By only one step of attaching the masking film 20 to the flexible flat cable 10, the flexibility The flat cable 10 imparts a shielding effect, and can also impart an impedance control effect to the flexible flat cable 10.

(Layer 21, 23)

The adhesive layers 21 and 23 contained in the mask film 20 are composed of olefin-based, urethane-based, vinyl acetate-based, polyester-based, polyamide-based, rubber-based, and Thermoplastic resins such as acrylic resins, or thermosetting resins such as phenol resins, epoxy resins, urethane resins, melamine resins, polyimide resins, and alkyd resins. The insertion layer 22 can be adhered to the flexible flat cable 10 by the adhesion layer 21. In addition, the metal thin film layer 24 can be adhered to the insertion layer 22 by the adhesive layer 23.

If the mask film 20 having the above configuration is used, when the conductive member 30 is connected to the mask film 20 including the cover film 25, the metal thin film layer 24, and the adhesive layer 23 by heating and pressing, the mask The cover film 25 made of resin in the film 20 is softened by heating, and when connected, the layer thickness L1 of the cover film 25 protrudes more than the average of the conductive particles 35 protruding from the conductive adhesive layer 33 in the conductive member 30 Since the length L2 is thinner, the conductive particles 35 protruding from the conductive adhesive layer 33 due to pressure can penetrate the cover film 25 in the mask film 20 and reach the metal thin film layer 24. Thereby, since the potential of the metal thin film layer 24 in the mask film 20 can be set to the ground potential through the conductive particles 35, there is no need to connect the ground conductor and the mask in the substrate to which the mask film 20 is attached as in the past The metal thin film layer 24 in the film 20 is connected. Therefore, there is no need to process the substrate in advance to expose the ground conductor, and no processing cost is consumed. In addition, since only the conductive member 30 is connected to the mask film 20, even when, for example, a long substrate is used, the mask film 20 can be easily grounded at a desired position.

(Flexible flat cable 10)

Next, the flexible flat cable 10 attached to the mask film 20 having the above-mentioned configuration will be described. As shown in FIG. 1, the flexible flat cable 10 has the following structure: on the base film 14, a plurality of conductors including a signal conductor 11 and a ground conductor 12 are arranged side by side in the width direction, and are provided on the plurality of conductors着 INSULATION FILM 13.

Both the base film 14 and the insulating film 13 are formed of engineering plastic. For example, polyethylene terephthalate, polypropylene, cross-linked polyethylene, polyester, polybenzimidazole (polybenzimidazole), polyimide, polyimide, polyimide, polyetherimide (polyetherimide), and polyphenylene sulfide (Poly Phenylene Sulfide, PPS) and other resins. When heat resistance is not so much required, an inexpensive polyester film is preferred, when flame retardancy is required, a polyphenylene sulfide film is preferred, and when heat resistance is required, a polyimide film is preferred.

In addition, when the base film 14 is joined to the signal conductor 11 and the ground conductor 12, it may be adhered by an adhesive, or the resin may be extruded.

In addition, as shown in FIG. 3, a reinforcement plate 40 is provided at the end of the flexible flat cable 10 to improve the strength of the connector insertion portion of the flexible flat cable.

The flexible flat cable 10 having the above configuration stabilizes the circuit signal by the metal thin film layer 24 in the mask film 20. Moreover, the flexible flat cable 10 has an electromagnetic shielding effect under the action of the shielding film 20.

In addition, the mask film 20 can be used not only for flexible flat cables, but also for flexible printed circuits (FPC), chip-on-chip flexible circuit boards (COF), and RF (flexible printed boards) ), Multilayer flexible substrates, rigid substrates, etc., but not necessarily limited to these substrates.

In addition, as shown in FIG. 2, the ground conductor 12 of the flexible flat cable 10 is connected to the external ground member such as the housing of the incorporated electronic device like the conductive member 30, whereby the ground conductor 12 and the conductive member 30 reach The same ground potential. Furthermore, as described above, the conductive member 30 and the mask film 20 can be set to the same potential via the conductive particles 35, and therefore, the mask film 20 and the ground conductor 12 can be set to the same ground potential.

(Mask wiring board 1)

Next, the mask wiring board 1 composed of the mask film 20 and the flexible flat cable 10 will be described.

As shown in FIGS. 1 and 3, the mask wiring board 1 of the present invention has the following structure: attached to one or both sides of a flexible flat cable 10 (FFC) by a mask film 20, or wrapped On both sides of the flexible flat cable 10, the conductive member 30 is connected to the shielding film 20.

As described above, since the conductive member 30 is connected to the mask film 20, the mask film 20 can be grounded by the conductive member 30 connected to an external ground member such as a casing.

(Grounding method of mask film 20)

Next, the grounding method of the mask film 20 will be described in detail using FIGS. 4 (a) and 4 (b).

As shown in FIGS. 4 (a) and 4 (b), the grounding method of the mask film 20 of the present invention includes a cover film 25 formed of resin, and a metal thin film layer 24 sequentially stacked on the cover film 25 and The grounding method of the mask film 20 of the next layer 23, the conductive member 30 includes a metal layer 32 connected to an external ground member in a contact state and a conductive adhesive layer 33 containing conductive particles 35 at a temperature at which the resin softens The conductive member 30 is heated and pressurized to bond the conductive adhesive layer 33 and the cover film 25, whereby the conductive particles 35 protruding longer than the layer thickness L1 of the cover film 25 reach the metal thin film layer 24 To ground.

First, as shown in FIG. 4 (a), the conductive member 30 held at the ground potential is aligned with the mask film 20 and heated from the conductive member 30 side. The heating temperature at this time is set in the range of 100 ° C. to 140 ° C. to soften the cover film 25 formed of the resin. By this heating, the cover film 25 starts to soften. In addition, the heating temperature at this time is preferably 120 ° C. to 135 ° C. If the heating temperature is less than 100 ° C., sufficient adhesion cannot be obtained. In addition, if the heating temperature exceeds 140 ° C, damage to the flexible flat cable 10 is caused, which is not good. Next, after the cover film 25 is heated, the mask film 20 is pressed from the conductive member 30 side, whereby the conductive adhesive layer 33 in the conductive member 30 is further adhered to the cover film 25. At this time, the cover film 25 has adhesiveness due to softening, and the conductive particles 35 protruding from the conductive adhesive layer 33 enter the cover film 25. Here, when the mask film 20 and the conductive member 30 are connected, the average protrusion length L2 of the conductive particles 35 protruding from the conductive adhesive layer 33 is longer than the layer thickness L1 of the cover film. The side is further pressurized, and the conductive particles 35 will penetrate the cover film 25 and reach the metal thin film layer 24.

As a result, as shown in FIG. 4 (b), the metal layer 32 and the metal thin film layer 24 are brought into a conductive state via the conductive particles 35, so that the potential of the metal thin film layer 24 can be set to the ground potential.

As such, according to the grounding method, when the conductive member 30 is connected to the mask film 20 including the cover film 25, the metal thin film layer 24, and the adhesive layer 23 by heating and pressing, the resin in the mask film 20 The formed cover film 25 is softened by heating, and when connected, the layer thickness L1 of the cover film 25 is thinner than the average protrusion length L2 of the conductive particles 35 protruding from the conductive adhesive layer 33 in the conductive member 30, so The conductive particles 35 protruding from the conductive adhesive layer 33 due to the pressure can penetrate the cover film 25 in the mask film and reach the metal thin film layer 24. Thereby, since the potential of the metal thin film layer 24 in the mask film 20 can be set to the ground potential through the conductive particles 35, there is no need to connect the ground conductor and the mask in the substrate to which the mask film 20 is attached as in the past The metal thin film layer 24 in the film 20 is connected. Therefore, there is no need to process the substrate in advance to expose the ground conductor, and it does not consume processing costs. In addition, since only the conductive member 30 is connected to the mask film 20, even when, for example, a long substrate is used, the mask film 20 can be easily grounded at a desired position.

(Manufacturing method of mask film 20)

Next, a method of manufacturing the mask film 20 will be described using FIG. 5.

As shown in FIG. 5, the manufacturing method of the mask film 20 of this embodiment includes: a roll-out step to roll out the metal thin film layer 24 wound into a roll shape; a cover film forming step to form a cover on the metal thin film layer 24 Film 25; adhesive layer forming step, forming adhesive layer 23 on metal thin film layer 24; insertion layer forming step, bonding adhesive layer 22 with adhesive layer 21 by adhesive layer 23 to form masking film 20; and winding step , The formed mask film 20 is wound into a roll shape.

Specifically, first, in the unwinding step, the rolled metal film layer 24 set on the unwinding machine 41 is rolled out. Then, while the rolled metal thin film layer 24 is guided by a roller, the metal thin film layer 24 is moved to the coating device 42.

Next, in the coating film forming step, the epoxy resin or the like is applied to the metal thin film layer 24 by the coating device 42 and dried in the drying furnace 43 to form the coating film 25. Then, while being guided by the guide roller again, it moves to the coating device 44.

Next, in the adhesive layer forming step, the thermoplastic resin or thermosetting resin is applied to the metal thin film layer 24 on which the cover film 25 is formed by the coating device 44 and dried in the drying furnace 45 to form the adhesive layer twenty three.

Then, in the interlayer formation step, the interlayer 22 having the adhesion layer 21 separately manufactured in advance is attached to the metal thin film layer 24 on which the cover film 25 and the adhesion layer 23 are formed by the bonding machine 46, thereby Manufacturing mask film 20.

Finally, while guiding the completed mask film 20 by a guide roller, the mask film 20 is gradually wound into a roll shape by a winding machine 47. Thereby, the mask film 20 of this embodiment can be manufactured.

In the above, one embodiment of the present invention has been described. Furthermore, the present invention is not necessarily limited to the above-mentioned embodiment.

For example, in the case of this embodiment, the cross-section of the conductive particles 35 has a circular shape, but it is not necessarily limited to this, as long as it is in contact with the metal layer 32 at the time of connection and protrudes from the conductive adhesive layer 33 on average When the length L2 is longer than the layer thickness L1 of the cover film 25, the cross section of the conductive particles 35 may also have a circular shape (as long as it is an elliptical shape, an egg shape, etc. with a curved shape), dendrite (dendrite ) Shape, scale shape, needle shape, chain shape, spike shape, etc. Furthermore, it is preferably circular.

In addition, in FIGS. 4 (a) and 4 (b), the conductive member 30 has a configuration in which one conductive particle 35 is included in the thickness direction of the conductive adhesive layer 33 and a plurality of the conductive particles 35 are arranged In the width direction of the conductive adhesive layer 33, the present invention is not necessarily limited to this. For example, the conductive particles 35 contained in the thickness direction of the conductive adhesive layer 33 are not limited to one, and a plurality of conductive particles 35 may be continuously arranged in a conductive state in contact with each other according to the particle diameter of the conductive particles 35 The adhesive layer 33 is in the thickness direction.

In addition, in the manufacturing method of the mask film 20 of FIG. 5, the interposer layer 22 in which the adhesive layer 21 is formed in advance is bonded to the metal thin film layer 24 on which the cover film 25 and the adhesive layer 23 are formed by the bonding machine 46 However, it is not necessarily limited to this, and the insertion layer 22 and the adhesion layer 21 may be sequentially formed on the metal thin film layer 24 on which the cover film 25 and the adhesion layer 23 are formed.

The examples of the present invention have been described above, but only specific examples have been exemplified, the present invention is not particularly limited, and specific configurations and the like can be appropriately designed and changed. In addition, the actions and effects described in the embodiments of the invention only list the best actions and effects produced by the present invention, and the actions and effects of the present invention are not limited to the actions and effects described in the embodiments of the present invention.

The present invention can be applied to a mask film used on a substrate having a conductor such as a flexible flat cable, and a mask wiring board having a mask film.

The above is only the preferred embodiments of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed in the preferred embodiments as above, it is not intended to limit the present invention. Anyone familiar with the profession Technical personnel, without departing from the scope of the technical solution of the present invention, when the above disclosed structure and technical content can be used to make some changes or modifications to equivalent equivalent embodiments, but any content that does not depart from the technical solution of the present invention is based on Any simple modifications, equivalent changes, and modifications made to the above embodiments by the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

1. . . Shield wiring board

10. . . Flexible flat cable

11, 51, 61. . . Signal conductor

12, 52, 62. . . Grounding conductor

13. . . Insulating film

14, 63. . . Base film

20. . . Masking film

21, 23, 53. . . Next layer

twenty two. . . Insert layer

twenty four. . . Metal film layer

25. . . Cover film

30. . . Conductive member

31. . . Plating layer

32, 56. . . Metal layer

33, 55, 59, 65, 68. . . Conductive adhesive layer

34. . . Adhesive

35. . . Conductive particles

40. . . Reinforcing plate

41. . . Unwinding machine

42, 44. . . Coating device

43, 45. . . Drying furnace

46. . . Laminating machine

47. . . Winding machine

50. . . Flexible flat cable

54. . . Foam insulator

57, 67, 70. . . Insulating film

58, 71. . . Non-insulated part

60. . . Impedance control shield wiring board

64. . . Insulation

66. . . Open metal film layer

69. . . Non-opening metal film layer

E. . . Circle

L1. . . Layer thickness

L2. . . Average protruding length

FIG. 1 is a cross-sectional view taken along line AA ′ of FIG. 2 of the mask wiring board according to the embodiment of the present invention.

2 is a diagram showing the appearance of a mask wiring board according to an embodiment of the present invention.

3 is a cross-sectional view taken along line BB ′ of FIG. 2 of the mask wiring board according to the embodiment of the present invention.

FIG. 4 (a) is a diagram showing a method before grounding the mask film in the embodiment of the present invention, before connecting the conductive member and the mask film. 4 (b) is a diagram showing a method of connecting the conductive member and the mask film in the method of grounding the mask film according to the embodiment of the present invention.

5 is a diagram showing a method of manufacturing a mask film according to an embodiment of the present invention.

6 is a diagram showing a cross section of the flexible flat cable of Patent Document 1. FIG.

7 is a diagram showing a cross section of an impedance control mask wiring board of Patent Document 2. FIG.

1. . . Shield wiring board

10. . . Flexible flat cable

11. . . Signal conductor

12. . . Grounding conductor

13. . . Insulating film

14. . . Base film

20. . . Masking film

21, 23. . . Next layer

twenty two. . . Insert layer

twenty four. . . Metal film layer

25. . . Cover film

30. . . Conductive member

33. . . Conductive adhesive layer

35. . . Conductive particles

E. . . Circle

L1. . . Layer thickness

L2. . . Average protruding length

Claims (1)

A flexible flat cable includes: a conductive member having a metal layer and a conductive adhesive layer containing conductive particles; a cover film formed to be more conductive than the conductive adhesive layer The average protruding length of the sex particles is a thinner layer thickness, and is followed by the conductive adhesive layer; a mask film, the mask film having a metal thin film layer, an adhesive layer, and an insertion layer that are sequentially stacked on the cover film; And a substrate with a ground conductor, the substrate with a ground conductor is connected to the insertion layer, and the conductive member and the ground conductor are not electrically connected.