JP2000269632A - Shield flexible printed wiring board, manufacture thereof and reinforcing shield film therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield flexible printed wiring board which is superior in electromagnetic wave shielding property and flexibility. SOLUTION: A shielding layer 8 is installed on one face of a cover film 7, an adhesive film 6 that can be peeled is bonded to the other face, and a reinforcing shield film 1 is formed. The film is loaded on a substrate film 5 containing a print circuit, and it is heated/pressurized and are bonded. Then, the adhesive film 6 is peeled. Consequently, a thin and flexible shield flexible printed wiring board is manufactured with good workability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a shielded flexible printed circuit board used in an apparatus such as a computer, a communication device, a video camera, etc., a reinforcing shield film used in manufacturing a shielded flexible printed circuit board, and a method of manufacturing the same. The present invention relates to a shielded flexible printed wiring board manufactured using the same.

[0002]

2. Description of the Related Art Flexible printed wiring boards (hereinafter referred to as "F
PCs) are frequently used in electronic devices such as cellular phones, video cameras, and notebook computers, which are rapidly becoming smaller and more sophisticated, in order to incorporate circuits into complicated mechanisms. Further, by utilizing its excellent flexibility, it is also used for connection between a movable unit such as a printer head and a control unit. In these electronic devices, electromagnetic wave shielding measures are indispensable, and flexible printed wiring boards (hereinafter, also referred to as "shield FPC") with electromagnetic wave shielding measures are used in FPCs used in the devices. It has become.

[0003] Conventional shield FPCs include those obtained by winding a copper foil of the FPC itself serving as a base, and those using a base FP.
There is a material in which a copper foil, an aluminum foil, or the like is adhered on C with an adhesive, or a material in which conductive fibers are adhered on a base FPC with an adhesive. Of these, those having poor flexibility have poor work efficiency in assembling and cannot be used for movable parts. In this case, the winding must be performed after the punching process, which is troublesome and expensive. Although they have improved flexibility, they are more expensive and less versatile.

To solve these problems, as shown in FIG. 5, a printed circuit 42 is formed on a base film 41, and an insulating layer 44, a conductive paste applied shield layer 45, In some cases, a coat layer 46 is sequentially provided. A shield FPC has been proposed in which a through-hole 47 is provided in a part of the insulating layer 44 on the ground circuit 43, and the conductive paste is connected to the ground circuit when the conductive paste is applied on the insulating layer 44. (See Japanese Patent Publication No. 6-34473).

[0005]

SUMMARY OF THE INVENTION This shield FPC
Has the advantage that it can be formed into any shape because the shield layer is formed by screen printing, but the process of printing and curing the conductive paste is added, and new equipment such as a printing machine and curing oven is required. There are problems such as becoming. In addition, since the conductivity of the conductive paste layer is inferior to copper foil or the like, in order to improve the electromagnetic wave shielding property, the thickness of the layer must be increased, and when it is increased, the flexibility is lost. There's a problem.

Therefore, the present inventors have prepared a shield film in which a conductive adhesive layer having good conductivity such as an adhesive containing copper powder is provided on an insulating film in advance, and the shield film is mounted on a base film. Then, a method of manufacturing a shielded flexible printed wiring board by simply applying heat and pressure to bond the same was considered. Further, in order to further improve the electromagnetic wave shielding property, for example, by providing a thin metal vapor deposition layer on an insulating film and providing a conductive adhesive layer thereon, the thickness of the conductive adhesive layer is significantly reduced. In addition, they considered improving the electromagnetic wave shielding property. However, it has been found that the method of integrating these thin shields by heating and pressing on the base film has the following problems. Since the shield film is thin, when punching it into a predetermined size, the edge does not become a sharp straight line, and the protruding conductive portion may come into contact with another layer. The shielding film is thin and soft, making it difficult to position on the base film. Since the insulating film and the metal vapor-deposited layer are thin, the cushioning effect during heating and pressurizing is small, the flow of conductive adhesive into the part of the ground circuit where the insulating film has been removed is small, the connection conductivity is poor, and the electromagnetic wave shielding property is low. May decrease.

The present invention solves the above problems and provides a method for easily manufacturing a shielded flexible printed wiring board excellent in both electromagnetic shielding properties and flexibility, and a shielded flexible printed wiring suitable for use therefor. An object is to provide a reinforcing shield film for a board.

[0008]

According to a first aspect of the present invention, there is provided a method of manufacturing a shielded flexible printed wiring board, comprising the steps of: forming a cover film on a base film including a printed circuit; One side is provided with a shield layer, and the other side is laminated with a peelable adhesive film having an adhesive property to form a reinforcing shield film, and the reinforcing shield film is mounted on the base film so that the shield layer abuts. Place
The method is characterized in that the adhesive film is peeled off after bonding by heating and pressing. Since the reinforcing shield film is thicker than the shield film, it can be easily punched into a predetermined size, can be cut neatly, and can be easily positioned on the base film. So the edges are cut off,
There is no danger of the protruding conductive portion coming into contact with another layer. In addition, since the reinforcing shield film is peeled off, a thin and flexible flexible printed circuit board having excellent flexibility can be easily obtained.

[0009] The reinforcing shield film for a shielded flexible printed wiring board according to the present invention is characterized in that a cover film has a shield layer on one side and a peelable adhesive film on the other side. Features. By punching this reinforcing shield film into a predetermined size, positioning it on the base film, and applying heat and pressure, it can be easily bonded to the base film. After bonding, the adhesive film of the reinforcing shield film is peeled off. This makes it possible to easily obtain a thin and flexible shielded flexible printed wiring board.

According to a third aspect of the present invention, there is provided the reinforcing shield film for a shielded flexible printed wiring board according to the second aspect, wherein the shield layer is formed of a metal thin film layer and a conductive layer on one surface of the cover film. And an adhesive layer. By providing the metal thin film layer, it is possible to obtain a shield film that is thinner, has better flexibility, and is excellent in electromagnetic wave shielding properties.

According to a fourth aspect of the present invention, there is provided a reinforcing flexible film for a shielded flexible printed wiring board.
The reinforced shield film for a shielded flexible printed wiring board according to the above, wherein the conductive adhesive layer is made of a metal filler-containing adhesive. Since the conductive adhesive layer is made of a metal filler-containing adhesive, a shield film having any flexibility and electromagnetic wave shielding properties can be obtained by selecting a metal filler, selecting an adhesive resin, selecting a compounding ratio, and the like.

According to a fifth aspect of the present invention, there is provided a shielded flexible printed wiring board reinforcing shield film according to the fourth aspect, wherein the metal filler-containing adhesive comprises a silver-coated copper filler. It is characterized by comprising a conductive resin. The silver-coated copper filler is less expensive than the silver filler, is more conductive than the copper filler, and provides a shielding film having excellent electromagnetic wave shielding properties.

According to a sixth aspect of the present invention, there is provided a shielded flexible printed wiring board comprising the reinforcing seed film according to the second aspect and an insulating layer provided on a printed circuit except for a part of a ground circuit. After being placed on a film and heated and pressed so that the conductive adhesive of the reinforcing shield film adheres to a part of the insulating layer and the ground circuit of the base film, the adhesive film is peeled off. It is characterized by the following. Since the reinforcing shield film is thicker than the shield film, it can be easily punched into a predetermined size, can be punched cleanly, and can be easily positioned on the base film. In addition, at the time of heating and pressurizing, the cushioning effect is increased by the adhesive film, the flow of the conductive adhesive into the non-insulated portion of the ground circuit is facilitated, and the connection conductivity is improved.

According to a seventh aspect of the present invention, there is provided the shielded flexible printed wiring board according to the sixth aspect, wherein the conductive adhesive is added to the silver-coated copper filler based on 100 parts by weight of the adhesive resin. 4
It is characterized by containing 00 parts by weight. The silver-coated copper filler is less expensive than the silver filler and more excellent in conductivity than the copper filler. Since the content is 400 parts by weight or less, it is excellent in adhesion and flexibility, and is 10 parts by weight or more. Therefore, it has excellent conductivity.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram of a method for manufacturing a shielded flexible printed wiring board of the present invention, and FIG. 2 is a cross-sectional view of a reinforcing shield film used when manufacturing the shielded flexible printed wiring board. FIG. 1 (a) is formed on a base film 2,
The reinforcing shield film 1 is placed on the base film 5 covered with the insulating film 4 except for at least a part 3c of the ground circuit 3b in the printed circuit 3 including the ground circuit 3a and the signal circuit 3b. P (P
_A, while heating h at P _B), shows a state in which the pressure p.

As shown in FIG. 2A, which will be described later, the reinforcing shield film 1 has a conductive adhesive layer 8a on one side of a cover film 7 with a metal thin film layer 8b interposed therebetween.
Is formed by bonding a peelable and sticky adhesive film 6 on a shield film 9 provided with. Here, the conductive adhesive layer 8a and the metal thin film layer 8b
Thus, the shield layer 8 is formed. The conductive adhesive 8a softened by the heating h is applied to the insulation removing portion 4a by the pressure p.
As shown by the arrow.

After the conductive adhesive 8a has sufficiently adhered to the non-insulating portion 3c and the insulating film 4 of the ground circuit 3b, as shown in FIG. 1B, the formed reinforcing shield flexible printed wiring board 10 is formed. Is taken out of the press P, and the adhesive film 6 of the reinforcing shield film 1 is removed.
Is peeled off, a shielded flexible printed wiring board 20 shown in FIG. 1C is obtained.

As shown in FIG. 2 (a), the reinforcing shield film 1 has a more adhesive film 6 than a shield film 9.
Therefore, it can be easily punched into a predetermined size, can be cut cleanly, and can be easily positioned on the base film 5. Further, at the time of heating and pressurizing, the cushion effect is increased by the adhesive film 6, and the pressure is transmitted gently, so that the flow of the conductive adhesive 8a into the insulation removing portion 4a is facilitated. Therefore, the exposed portion 3c of the ground circuit
Since it is sufficiently adhered to the surface, connection conductivity is improved. Also,
By peeling off the adhesive film 6, a thin and flexible shielded flexible printed wiring board 20 can be easily obtained.

FIG. 2 is a cross-sectional view of a reinforcing shield film used in the method of manufacturing the shield flexible printed wiring board. As described above, the reinforcing shield film 1 shown in FIG. 2A is obtained by laminating the peelable and sticky adhesive film 6 on the shield film 9 in which the shield layer 8 is provided on one surface of the cover film 7. It was formed. The shield layer 8 includes a conductive adhesive layer 8a and a metal thin film layer 8b.

The reinforcing shield film 1 'shown in FIG.
2A is different from that shown in FIG. 2A in that a shield layer 8 'consisting of only a conductive adhesive layer is provided on one surface of a cover film 7 to form a shield film 9'. Since the conductivity of the metal thin film layer is better than that of the conductive adhesive layer, the shield layer can be made thinner by providing the metal thin film layer as shown in FIG. The configuration of the shield layer is not limited to this, but a layer having good conductivity and flexibility is preferable.

The base film 2, the insulating film 4, and the cover film 7 are all made of engineering plastic. For example, polypropylene, cross-linked polyethylene, polyester, polybenzimidazole, polyimide, polyimide amide, polyetherimide, polyphenylene sulfide (PPS) and the like can be mentioned. When heat resistance is not required so much, an inexpensive polyester film is preferable. When flame retardancy is required, a polyphenylene sulfide film is preferable. When heat resistance is required, a polyimide film is preferable.

As the adhesive film 6, the same engineering plastic as the base film 2, the insulating film 4, and the cover film 7 is used, but an inexpensive polyester film is preferable because it is removed during the manufacturing process. The adhesive strength with the cover film 7 is
Preferably it is in the range of 5 to 200 g / cm.
If it is less than 200 cm, it may be peeled off during punching and alignment work, and if it is more than 200 g / cm, the product may be an obstacle when peeling the adhesive film. Further, it is more preferably 20 to 100 g / cm.

Examples of the method for imparting adhesive force to the surface of engineering plastics include a method of physically or chemically treating the surface and a method of coating the surface with an adhesive material. When the adhesive film 6 is peeled, it is necessary that the adhesive does not transfer to the surface of the cover film 7.

The conductive adhesive layers 8a and 8 'are made of an adhesive resin containing a conductive filler such as metal and carbon. Adhesive resins include thermoplastic resins such as polystyrene, vinyl acetate, polyester, polyethylene, polypropylene, polyamide, rubber, and acrylic, phenolic, epoxy, urethane, melamine, and alkyd. A thermosetting resin such as a resin is used. When heat resistance is not particularly required, a polyester-based thermoplastic resin that is not restricted by storage conditions and the like is desirable, and when heat resistance or better flexibility is required, after forming the shield layer A highly reliable epoxy-based thermosetting resin is desirable. In all cases, bleeding during hot pressing (resin flow)
Needless to say, a smaller one is desirable.

As the metal filler, a silver-coated copper filler obtained by applying silver plating to silver, copper, nickel, solder, aluminum and copper powder, a filler obtained by applying metal plating to resin balls, glass beads, or the like, or these fillers Is used. Silver is expensive, copper lacks reliability in heat resistance, aluminum lacks reliability in moisture resistance, and it is difficult for solder to obtain sufficient electrical conductivity. It is preferable to use a silver-coated copper filler or nickel having high reliability.

The mixing ratio of the metal filler to the adhesive resin depends on the shape of the filler and the like.
The amount is preferably from 400 to 400 parts by weight, more preferably from 20 to 150 parts by weight. If the amount exceeds 400 parts by weight, the adhesion to the ground circuit (copper foil) decreases, and the flexibility of the shield FPC deteriorates. If the amount is less than 10 parts by weight, the conductivity is significantly reduced. In the case of nickel filler, 40 to 40 parts by weight of the adhesive resin is used.
It is preferably 400 parts by weight, more preferably 1 part by weight.
The content is preferably in the range of 00 to 350 parts by weight. If the amount exceeds 400 parts by weight, the adhesion to the ground circuit (copper foil) decreases, and the flexibility of the shield FPC deteriorates. If the amount is less than 40 parts by weight, the conductivity is significantly reduced. The shape of the metal filler may be spherical, needle-like, fibrous, flake-like, or resin-like.

Examples of the metal material for forming the metal thin film layer 8b include aluminum, copper, silver, gold and the like. The metal material may be appropriately selected according to the required shielding properties, but copper has a problem that it is easily oxidized when exposed to the air, and gold is expensive, so cheap aluminum or highly reliable silver is used. preferable. The film thickness is appropriately selected according to the required shielding characteristics and flexibility.
It is preferably from 0.01 to 1.0 μm. If the thickness is less than 0.01 μm, the shielding effect becomes insufficient.
If it exceeds, the flexibility becomes poor. As a method for forming the metal thin film layer 8b, vacuum deposition, sputtering, CVD, M
Although there is O (metal organic) and the like, vacuum deposition is desirable in consideration of mass productivity, and a cheap and stable metal thin film layer can be obtained.

FIG. 3 is a cross-sectional view of the shielded flexible printed wiring board obtained as described above.
(a) is the same as FIG. 1 (c). The shielded flexible printed wiring board of the present invention naturally includes a shielded flexible printed wiring board in which the shield layer is formed only of the conductive adhesive layer 8 'as shown in FIG. 2 (b) instead of the shield film 9 of FIG. 3 (a). . Also,
Various materials and forming methods for the shield film are also included as described above.

Further, not only a single-sided shield but also a double-sided shield as shown in FIGS. 3 (b) and 3 (c) are included. In the double-sided shield flexible printed wiring board 20 shown in FIG. 3B, the base film 2 'is formed so that the conductive adhesive layer is connected to the ground circuit 3b.
Insulated portions 4a and 2'a are provided on the upper and lower sides of the ground circuit 3b on the insulating film 4 and base film 2 'side, and are connected to the conductive adhesive layer 8a on the upper and lower surfaces 3c of the ground circuit 3b. Here, the base film 2 ', the printed circuit 3 (the signal circuit 3a and the ground circuit 3b), and the insulating film 4 constitute a base film 5'.

The double-sided shielded flexible printed wiring board 31 shown in FIG. 3 (c) is similar to the ground circuit 3 shown in FIG. 3 (b).
b Insulation removal parts 4a and 2'a are provided on the upper and lower insulating films 4 and the base film 2 'side, and a through hole 3'd is further provided in the ground circuit 3b to form a ground circuit 3'b. Then, the conductive adhesive layer 8a enters the through hole 3'd from both sides and merges at the interface s. The ground circuit 3 'is connected to the conductive adhesive layer 8a on the upper surface 3c and the inner surface 3'c of the through hole. Here, the base film 2 'and the printed circuit 3'
(The signal circuit 3'a and the ground circuit 3'b) and the insulating film 4 constitute a base film 5 ".

Since the reinforcing shield film is thicker than the shield film, it can be easily punched into a predetermined size, can be cut neatly, and can be easily positioned on the base film. Further, at the time of heating and pressing, the cushion effect is increased by the adhesive film, and the insulation removing portions 4a and 2'a
And the flow of the conductive adhesive into the through hole 3'd is facilitated,
Connection conductivity is improved. Therefore, these shielded flexible printed wiring boards are thinner and more flexible than conventional ones, and are excellent in electromagnetic wave shielding because the conductive adhesive and the ground circuit are securely connected.

[0032]

EXAMPLES The characteristics of the shield FPC obtained as described above were evaluated, and will be described in comparison with a conventional example. The shield FPCs of Examples 1 to 7 had the single-sided shield structure shown in FIG. 3A, and the constituent materials and dimensions of the reinforcing shield film were as shown in Table 1, and were manufactured by the method shown in FIG. The metal thin film layer 8b is formed by evaporating silver to a thickness of 0.1 mm, and the conductive adhesive layer 8a is coated with a metal filler-containing adhesive by a roll coating method, and is included in the resin component. Solvent component at 100 ° C 3-5
It was dried by heating for 20 minutes to a thickness of 20 μm. The adhesive film 6 for reinforcement used was a 25 μm polyester film coated with an adhesive material.

The base film 5 has a thickness of 25 μm
Fifteen linear copper foil circuits 3 were formed on a polyimide base film 2 by an etched foil method.
The thickness of the copper foil was 20 μm, the width was 1 mm, the interval was 1 mm, the two ground circuits 3b were used, and the rest was used as the signal circuit 3a. This was covered with a 25 μm-thick polyimide film 2 except for a part 3c of the upper surface of the ground circuit 3b. The reinforcing shield film 1 is placed on the base film 5 having a thickness of 70 μm thus obtained, and is heated and pressed by the press P under the processing conditions shown in Table 1 to apply the conductive adhesive to the upper surface 3c of the ground circuit 3b. After being adhered to the upper surface of the insulating film 4 and taken out from the press P, the adhesive tape 6 was peeled off to obtain Examples 1 to 7.

[0034]

[Table 1]

Comparative Example 1 is a shielded flexible printed wiring board having a shield layer formed by applying and curing a conductive copper paste by a screen printing method. Comparative Example 2 is a copper foil-wrapped shield flexible printed wiring board.

With respect to these examples and comparative examples, an adhesion test and a flexibility test were performed. The test method is as follows. (1) Adhesion test A copper foil and a polyimide film of a printed circuit were adhered to a glass epoxy substrate with a double-sided tape, and the shield films of the respective examples cut to a width of 10 mm were overlapped and heated and heated under the processing conditions shown in Table 1. After pressing and bonding, only the margins at both ends of the material were peeled off, gripped with a chuck, and pulled at a speed of 50 mm / min by a tensile tester to obtain a sample 10
mm was peeled off, and the tensile strength was measured.
And the sample having a value of 300 gf / cm or more was regarded as good. (2) Flexibility test As a method for evaluating flexibility, a reciprocating sliding test was performed. As shown in FIG. 4, one end of the shielded flexible printed wiring board 20 is fixed to a fixture F, and a radius of curvature R = 5.
mm, and the other end is reciprocated in the horizontal direction by the moving tool M at a moving distance L of 25 mm and a reciprocating movement speed of 1000 times / min, and reciprocating until the conductor is disconnected by a disconnection detecting circuit provided separately. Measure the number of times. The case where the number of times until the conductor was disconnected was 1,000,000 times or more was evaluated as “○”, and the case where the number of times was less than 1,000,000 times was evaluated as “X”.

As a result of the test, the results of the adhesion test were all good. Further, the thickness of the finished product from which the adhesive film 6 was peeled off and the results of the reciprocating slidability test are shown in the corresponding columns of Table 1. As is clear from the results in Table 1, the shielded flexible printed wiring board of the example had better results in the reciprocating sliding test than that of the comparative example, and was found to be excellent in flexibility. . This is a nod to the thickness of the finished product.

[0038]

As described above, according to the first aspect of the present invention, since the reinforcing shield film in which the adhesive film is bonded on the shield film in advance is thicker than the shield film, the reinforcing shield film has a predetermined size. It is easy to punch, can be cut neatly, and is easy to position on the base film. Therefore, the edge is cut off, and there is no possibility that the protruding conductive portion comes into contact with another layer.
Moreover, since the adhesive film is peeled off after heating and pressurizing, a thin and flexible shielded flexible printed wiring board can be obtained.

According to the second aspect of the present invention, since the cover film has a shield layer on one side and a peelable adhesive film attached to the other side, the cover film is thicker than the shield film. By punching out to a predetermined size and aligning it on the base film, or by applying heat and pressure, it is easy to adhere to the base film, and by peeling off the adhesive film of the reinforcing shield film after bonding, It is possible to easily provide a shielded flexible printed wiring board which is thin and excellent in flexibility.

According to the third aspect of the present invention, in addition to the effect of the second aspect of the present invention, since the shield layer is composed of the metal thin film layer and the conductive adhesive layer, it is thinner and more flexible. In addition, a shield film having excellent electromagnetic wave shielding properties can be obtained.

According to the fourth aspect of the invention, in addition to the effects of the second or third aspect, the conductive adhesive layer is made of a metal filler-containing adhesive, so that the selection of the metal filler and the adhesiveness By selecting a resin, selecting a compounding ratio, and the like, a shielding film having any flexibility and electromagnetic wave shielding properties can be easily obtained.

According to the fifth aspect of the invention, in addition to the effect of the fourth aspect, the metal filler-containing adhesive is
It is made of an adhesive containing silver-coated copper filler, and silver-coated copper filler is less expensive than silver filler and more excellent in conductivity than copper filler, so that a shielding film having excellent electromagnetic wave shielding properties can be obtained at low cost.

According to the invention of claim 6, the reinforcing shield film bonded on the shield film is made of the reinforcing seed film according to any one of claims 2 to 5, which has respective advantages and also has a shield. It is thicker than the film, so it is easy to punch into a predetermined size, it can be cut neatly, it is easy to align it on the base film, and the adhesive effect increases the cushioning effect when heating and pressing, and the insulation of the ground circuit The flow of the conductive adhesive into the parts that are not performed is easy, and the connection conductivity is improved, so that the electromagnetic wave shielding property is excellent, and since the adhesive film is peeled off after heating and pressing, it is also flexible. An excellent shield flexible printed wiring board can be obtained.

According to the seventh aspect of the present invention, in addition to the effects of the sixth aspect, the conductive adhesive is silver-coated copper which is less expensive than the silver filler and more conductive than the copper filler. Contains filler, the content of which is 100 parts by weight of the adhesive resin, the silver-coated copper filler 10
Since it is 400 parts by weight, it is excellent in adhesiveness and flexibility and also excellent in conductivity, so that a shielded flexible printed wiring board having particularly excellent flexibility and electromagnetic wave shielding properties can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method for manufacturing a shielded flexible printed wiring board according to the present invention.

FIG. 2 is a cross-sectional view of the reinforcing shield film for a shielded flexible printed wiring board of the present invention.

FIG. 3 is a cross-sectional view of the shielded flexible printed wiring board of the present invention.

FIG. 4 is an explanatory diagram of a flexibility test.

FIG. 5 is a perspective view of a conventional shielded flexible printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforcement shield film 2, 2 'base film 2'a Insulation removal part 3 3' Print circuit 3a Signal circuit 3b, 3'b Ground circuit 3c, 3 'Non-insulation part of ground circuit 3'd Through hole 4 Insulation film 4a Insulation removal part 5,5 ', 5 "Base film 6 Adhesive film 7 Cover film 8 Shield layer 8a Conductive adhesive layer 8b Metal thin film layer 9 Shield film 20 Single-sided shielded flexible printed wiring board 30, 31 Double-sided shielded flexible printed wiring Board

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shohei Morimoto 2-3-1 Iwatacho, Higashiosaka-shi, Osaka Tatsuta Electric Wire Co., Ltd. F-term (reference) 5E314 AA31 AA32 AA33 AA34 AA36 AA42 AA43 BB01 BB11 CC15 DD05 EE03 FF06 GG26 5E321 AA17 BB23 BB32 BB34 BB44 CC16 GG05 5E338 AA03 AA12 AA16 CC05 CD23 EE13

Claims (7)

[Claims] 1. A method according to claim 1, further comprising the steps of:
When coating the shield film, a shield layer is provided on one surface of the cover film, and a sticky adhesive film having a peelable adhesive property is attached to the other surface to form a reinforcing shield film, and the shield layer is formed on the base film. A method for manufacturing a shielded flexible printed wiring board, comprising: placing the reinforcing shield film so as to be in contact with the film, bonding the film by heating and pressurizing, and then peeling the adhesive film. 2. A reinforcing shield film for a shielded flexible printed wiring board, comprising a cover film having a shield layer on one surface and a peelable adhesive film adhered to the other surface. 3. The shielded flexible printed wiring board reinforcing shield film according to claim 2, wherein the shield layer is formed by sequentially providing a metal thin film layer and a conductive adhesive layer on one surface of a cover film. Reinforcing shield film for shield flexible printed wiring boards. 4. The reinforcing shield film for a shielded flexible printed wiring board according to claim 2, wherein the conductive adhesive layer is made of a metal filler-containing adhesive. Shield film. 5. The shielded flexible printed wiring board according to claim 4, wherein the metal filler-containing adhesive is made of an adhesive resin containing a silver-coated copper filler. Reinforcing shield film. 6. The reinforcing seed film according to claim 2, which is placed on a base film provided with an insulating layer that insulates a printed circuit except for a part of a ground circuit, and Shield flexible characterized in that the adhesive is heated and pressed so that the conductive adhesive of the reinforcing shield film adheres to the insulating layer of the base film and part of the ground circuit, and then the adhesive film is peeled off. Printed wiring board. 7. The shielded flexible printed wiring board according to claim 6, wherein the conductive adhesive contains 10 to 400 parts by weight of a silver-coated copper filler based on 100 parts by weight of the adhesive resin. Shield flexible printed wiring board.