KR101961234B1 - Shield film, shield printed wiring board and method of manufacturing shield printed wiring board - Google Patents

Abstract

The present invention provides a shield film, a shielded printed wiring board, and a method for manufacturing a shielded printed wiring board, which prevent defects caused by adhesion of a separate film to a protective layer by appropriately controlling the adhesive strength or adhesive strength to be too small. According to the present invention, the protective layer 7 is formed by coating the resin with the release layer 6b interposed therebetween on the side where the concave-convex portion 61 of the separate film 6a having the convex- And the surface roughness Ra of the protective layer 7 (hard layer 7a) when the separator film 6a is peeled off from the protective layer 7 is 0.2 占 퐉 The shielding film 1 can be manufactured to have a thickness of 1.0 to 1.0 mu m.

Description

TECHNICAL FIELD [0001] The present invention relates to a shield film, a shielded printed wiring board, and a shield printed wiring board,

The present invention relates to a shield film for shielding a printed wiring board or the like used in a device such as a computer, a communication device, a printer, a mobile phone, and a video camera, a shielded printed wiring board using the same, and a method of manufacturing the shielded printed wiring board.

A flexible printed wiring board (hereinafter also referred to as an " FPC ") is provided with a printed circuit without interposing an adhesive on at least one side of a flexible insulating film such as a polyimide film or a polyester film, A flexible insulating film having an opening corresponding to a terminal for mounting a circuit component on the upper surface of the printed circuit or a terminal for connection with an external substrate is adhered to the upper surface of the printed circuit through an adhesive, A surface protective layer is formed by a method such as coating, drying, exposure, development, or heat treatment, and the like. In the electronic devices such as mobile phones, video cameras, and notebooks, It is widely used for inserting a circuit in a mechanism. In addition, by utilizing the excellent flexibility, it is also used for connection between a movable portion such as a print head and a control portion. Measures for electromagnetic shielding of electronic equipment in which FPCs are variously used are required, and shielded flexible printed wiring boards (hereinafter referred to as "shield FPCs") that are provided with electromagnetic shielding measures have been used for FPCs used in the apparatus.

For example, in the shield FPC disclosed in Patent Document 1, a cover film (protective layer) is formed by coating resin on one side of a separate film with a releasing agent interposed therebetween, and a shield layer is attached to one side of the cover film A shield film is formed and the shield film is bonded by heating / pressing at least one surface of the FPC using a conductive adhesive agent. The shield layer and the ground circuit mounted on the FPC are electrically connected through a conductive adhesive agent. (See Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-95566

However, in the case of using a cover film (protective layer) coated with a releasing agent on one side of the separate film as described above, the degree of adhesion (peel strength) of the separate film to the cover film (protective layer) depends on the characteristics of the releasing agent, It is difficult to control the degree of adhesion (peel strength). Therefore, when the separator film is peeled off from the cover film (protective layer), the cover film (protective layer) itself is torn due to too large an adhesive force, or the separator film is peeled from the cover film There was a case in which it was peeled off.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a shield film, a shielded printed wiring board, and a method for manufacturing a shielded printed wiring board, which prevent defects caused by adhesion of too large adhesive force or too small adhesive force by appropriately controlling the adhesive strength of the separate film to the protective layer .

The shield film of the present invention is a shield film in which a protective layer is formed by coating a resin with a releasing agent interposed therebetween on a surface side where the concavo-convex portion of the separate film having concavo-convex portions formed on the entire one surface thereof is formed and an electromagnetic wave shield layer is further formed, And the surface roughness (Ra) of the protective layer when the film is peeled from the protective layer is 0.2 占 퐉 to 1.0 占 퐉.

The surface roughness (Ra) formed by transferring the convexo-concave portion of the surface of the separate film and the convexo-concave portion of the surface of the separate film in the state where the separate film is adhered to the protective layer via the releasing agent as in the above- Due to the anchoring effect of the concavo-convex portion, when the shield film is immersed in the chemical solution in the subsequent process, the protective film is prevented from peeling off from the protective layer because the chemical solution does not enter between the protective layer and the separator film, It is possible to increase the adhesiveness of the separate film to the film. Further, in the process of applying the releasing agent to the separate film having concave and convex portions, the releasing agent is naturally dispersed and almost evenly distributed, and the resin for the protective layer is applied and the surface roughness (Ra) formed by transferring the concave- A protective layer of about 1.0 mu m thick can be formed. Thereby, the adhesion of the separate film to the protective layer can be suppressed to such an extent that when the separate film is peeled from the protective layer, the protective layer itself is not torn due to too large an adhesive force. As described above, since the adhesive force of the separate film to the protective layer can be appropriately controlled, it is possible to prevent defects caused by adhesion with an excessively large adhesive force or too small adhesive force.

The shield film of the present invention is characterized in that the peel strength of the separate film to the protective layer is 1 N / 50 mm to 20 N / 50 mm.

According to the above configuration, the peel strength of the separate film to the protective layer is 1 N / 50 mm to 20 N / 50 mm, thereby making it possible to further optimize the adhesive force of the separate film to the protective layer.

The shield film of the present invention is characterized in that the peel strength of the separator film to the protective layer after the shield film is mounted on the printed wiring board and heated / pressed is 1 N / 50 mm to 10 N / 50 mm.

According to the above configuration, the separation strength of the separate film to the protective layer is set to 1 N / 50 mm to 10 N / 50 mm by mounting the shield film on the printed wiring board and heating / Can be made more optimal.

Further, the shield film of the present invention is characterized in that the electromagnetic wave shielding layer includes a conductive adhesive layer.

According to the above configuration, the ground circuit of the printed wiring board and the electromagnetic wave shielding layer can be electrically connected reliably.

Also, the shield film of the present invention is characterized in that the electromagnetic wave shielding layer further comprises a metal layer, and the conductive adhesive layer is composed of an anisotropic conductive adhesive layer.

According to the above configuration, since the amount of the conductive filler is small, excellent flexibility can be obtained.

The shield film of the present invention is characterized in that the conductive adhesive layer is composed of an isotropic conductive adhesive.

According to the above configuration, it is possible to provide a ground connection to a ground circuit or the like and to provide an electromagnetic wave shielding effect only by having a conductive adhesive layer.

The present invention also provides a method for forming a protective layer by coating a resin on at least one surface of a base body including one or more printed circuit boards with a releasing agent interposed therebetween on a surface of the separate film on which the concavo- And a shield film on which an electromagnetic wave shield layer is further formed, characterized in that the surface roughness (Ra) of the protective layer when the separate film is peeled off from the protective layer is 0.2 μm to 1.0 μm .

According to the above configuration, in the shield printed wiring board having the electromagnetic wave shielding layer and the protective layer on one surface of the base, in the state where the separate film is bonded to the protective layer with the release agent interposed therebetween, When the shield film is immersed in a chemical solution such as plating in a subsequent step owing to the anchor effect of the surface irregularity (Ra) formed by transferring the concavities and convexities and having the irregularities on the surface of the protective layer of 0.2 mu m to 1.0 mu m, The adhesion of the separate film to the protective layer can be enhanced to such an extent that the separate film does not enter between the separate films and can be prevented from peeling off from the protective layer. Furthermore, since the concavo-convex portion of the surface of the protective layer having the surface roughness (Ra) formed by transferring the concavo-convex portion of the surface of the separate film and the concavo-convex portion of the surface of the separate film is provided, The releasing agent can be dispersed and arranged almost uniformly. Thereby, the adhesion of the separate film to the protective layer can be suppressed to such an extent that when the separate film is peeled from the protective layer, the protective layer itself is not torn due to too large an adhesive force. As described above, since the adhesive strength of the separate film to the protective layer can be appropriately controlled, it is possible to prevent defects caused by adhesion with too large adhesive force or too small adhesive force.

Further, the shielded printed circuit board of the present invention is characterized in that the substrate including the printed circuit is formed of a flexible printed wiring board.

According to the above configuration, the shielded printed wiring board can have excellent flexibility.

The shield printed wiring board of the present invention is characterized in that the substrate including the printed circuit is a TAB tape for a tape carrier package.

According to the above configuration, a shielded printed wiring board which is flexible and excellent in insertion property can be obtained.

Further, the present invention is characterized in that a shield film obtained by laminating at least a releasing agent, a protective layer, and an electromagnetic wave shielding layer on the surface of the relief film side of the separator film, And the protective film is peeled off from the protective layer after the shield film and the substrate are heated / pressed in the laminating direction and the protective layer having a surface roughness (Ra) of 0.2 to 1.0 占 퐉 is formed, Layer on the surface of the shielded printed circuit board.

According to the above method, in the state where the separate film is bonded to the protective layer via the release agent, the surface roughness (Ra) formed by transferring the concavo-convex portion of the surface of the separate film and the concavo- The chemical solution does not enter between the protective layer and the separator film when the shield film is immersed in a chemical solution such as a plating solution in a subsequent process and thus the separator film can be prevented from being peeled off from the protective layer The adhesion of the separate film to the protective layer can be enhanced. Furthermore, since the concavo-convex portion of the surface of the protective layer having the surface roughness (Ra) formed by transferring the concavo-convex portion of the surface of the separate film and the concavo-convex portion of the surface of the separate film is provided, It is possible to make the release agent almost uniformly dispersed and arranged. Thereby, the adhesion of the separate film to the protective layer can be suppressed to such an extent that when the separate film is peeled from the protective layer, the protective layer itself is not torn due to too large an adhesive force. As described above, since the adhesive strength of the separate film to the protective layer can be appropriately controlled, it is possible to prevent defects caused by adhesion with too large adhesive force or too small adhesive force.

1 (a) and 2 (b) illustrate a method of manufacturing the shield FPC according to the present embodiment, wherein (a) shows a state in which a shield film is mounted on a base film and is pressurized while being heated by a press machine, (C) shows a state after peeling the separate film.
Fig. 2 is a cross-sectional view of a shield film used in manufacturing a shield FPC. Fig. 2 (a) shows an electromagnetic wave shielding layer formed of an adhesive layer and a metal layer, and Fig. 2 (b) shows an electromagnetic wave shielding layer formed of only an adhesive layer.
3 is an enlarged view of a part of the shield film in a cross-sectional view of the shield FPC.
4 is a cross-sectional view of the shield FPC, and Figs. 4B and 4C are cross-sectional views of the shield FPC of the both-side shield.
5 is a cross-sectional view of a shield FPC in a case where a protective layer constituting a shield film is formed in a single-layer structure.
Fig. 6 is a table summarizing the results of evaluation tests according to Examples and Comparative Examples. Fig.
7 is an explanatory diagram of an evaluation test method according to the embodiment and the comparative example.

Hereinafter, an example of an embodiment of a shield FPC according to the present invention will be described with reference to the drawings. Fig. 1 is an explanatory view of a method of manufacturing a shield FPC according to the present embodiment, and Fig. 2 is a cross-sectional view of a shield film used at the time of manufacturing the shield FPC. 1A is a plan view of the ground circuit 3b of the printed circuit 3 formed on the base film 2 and composed of the signal circuit 3a and the ground circuit 3b. The shield film 1 is mounted on the base film 5 covered with the insulating film 4 except for the step of pressing (p) while heating (h) with the press machine (P) State. 3 is an enlarged view of a portion of the shield film in a cross-sectional view of the shield FPC.

Here, the bonding of the base film 2 and the printed circuit 3 can be carried out using an adhesive, and the bonding may be carried out in the same manner as a so-called no-adhesive type copper-clad laminate, which does not use an adhesive. The insulating film 4 may be adhered using an adhesive, or may be formed by a series of methods such as coating, drying, exposure, development, and heat treatment of a photosensitive insulating resin. In addition, as the base film 5, a cross-sectional FPC having a printed circuit on only one side of the base film, a double-side FPC having a printed circuit on both sides of the base film, and a multilayer FPC , A Flex-board (registered trademark) having a multilayer component mounting portion and a cable portion, a flex-rigid substrate formed by hardening a member constituting a multilayer portion, or a TAB tape for a tape carrier package.

Here, the shield film 1 shown in Fig. 2 (a) is used. 2 (a), the shield film 1 includes a separate film 6a, a release layer 6b, and a shield film body 9. As shown in Fig. The shield film body 9 is formed by sequentially coating a hard layer 7a made of a resin having excellent abrasion resistance / blocking resistance and a soft layer 7b made of a resin having excellent cushioning property on a release layer 6b, And an adhesive layer 8a formed on the opposite surface of the protective layer 7 in contact with the release layer 6b and the metal layer 8b. Here, the electromagnetic wave shielding layer 8 is formed of the adhesive layer 8a and the metal layer 8b made of a conductive adhesive. In this electromagnetic wave shielding layer 8, the adhesive 8a 'softened due to the heating h flows into the insulation removal 4a as shown by the arrows due to the pressing force p (see Fig. 1 (a)), .

In addition, the protective layer 7 may not be a two-layer structure having a hard layer 7a and a soft layer 7b, or may have a single-layer structure as shown in Fig. In the case of adopting such a single layer structure, a thermosetting resin, a thermoplastic resin, an electron beam hardening resin, or the like can be used as the resin constituting the protective layer 7.

As shown in Fig. 3, the surface of the separate film 6a on the side of the protective layer 7 is subjected to a mat treatment. Concretely, fine sand is sprayed on one surface of the separate film 6a to form concave-convex portions 61 (convex portions 61a and concave portions 61b) on the surface so that one surface of the separate film 6a is concave and convex So that the surface area can be increased. Examples of the matte treatment include a sand mat, an etching mat, a coating mat, a chemical mat, and a kneading mat.

3, a plurality of concave-convex irregularities 71 are formed on the entire surface of the hard layer 7a constituting the protective layer 7 on the side of the separate film 6a . The concave-convex portion 71 is formed by a combination of the adjacent concave portion 71b and the convex portion 71a. The irregular portion 71 formed on the hard layer 7a is formed by coating the release layer 6b on one side of the separate film 6a and then removing the irregular portion 61 formed on one side of the separate film 6a, (See the enlarged view of Fig. 3). The surface roughness Ra of the surface on which the concave-convex portion 71 of the hard layer 7a is formed after the separation film has been peeled can be 0.2 mu m to 1.0 mu m, more preferably 0.2 mu m to 0.6 mu m Do.

The hard layer 7a constituting the protective layer 7 is formed so that the mass of the friction material is set to 500 g in accordance with the friction test method using a friction type tester (Japan Science Foundation) prescribed in JIS L 0849 And a soft layer 7b is formed of a resin having no abrasion resistance even when reciprocating 1,000 times at a speed of 120 mm reciprocating at a speed of reciprocating the specimen band 30 times per minute, And a modulus of elasticity measured at a frequency of 1 Hz, a measurement temperature range of -50 ° C to 150 ° C, and a temperature increase rate of 5 ° C / min according to the dynamic mechanical property test method specified in 4 above. The hard layer 7a having excellent abrasion resistance functions as a protective layer after peeling of the separate film 6a to separate the protective film 7 from the protective layer 7 in the subsequent process Prevent wear. Since the hard layer 7a is excellent in blocking resistance, the hard layer 7a is applied to other parts such as a transportation jig and a transportation belt for carrying a wiring board mounted thereon during a process requiring heating such as a reflow process in a circuit component mounting process Do not stick. The metal layer 8b formed on the soft layer 7b of the protective layer 7 is formed by the hardness of the hard layer 7a and the cushioning effect of the soft layer 7b, It does not cause fracture such as cracking / insulation even when it is pressurized. Further, due to the cushioning effect of the soft layer 7b, the shield film 1 is mounted on the base film 5 including the printed circuit 3 and then heated (h) by the press machines P: PA and PB, The pressure is transmitted smoothly to the hard layer 7a at the time of pressing (p), so that the hard hard layer 7a is prevented from cracking. As the resin for the hard layer and the soft layer, a thermosetting resin, a thermoplastic resin, an electron beam hardening resin, or the like can be used.

After the release layer 6b is coated on one surface of the separate film 6a, the releasing layer 6b is naturally dispersed and uniformly distributed, and the hard layer 7a of the protective layer 7 is coated The concave and convex portions 61 of the separate film 6a are transferred to the hard layer 7a to form a protective layer 7 having a surface roughness Ra of 0.2 mu m to 1.0 mu m ).

The releasing layer 6b is not particularly limited as long as it has releasability with respect to the protective layer 7. For example, a silicone, a non-silicone type melamine releasing agent, or a PET film coated with an acrylic releasing agent can be used. It is preferable that the maximum thickness of the release layer 6b is made thinner than the height of the irregularities formed on the surface of the separate film 6a by the mat treatment (if the thickness of the release layer 6b exceeds the height of the irregularities, It is difficult to control the peel strength of the separate film 6a with respect to the protective layer 7). The hard layer 7a and the soft layer 7b may be formed on one side of the separate film 6a by a coating method, but lamination, extrusion, dipping, or the like may be used.

The peel strength of the separate film 6a with respect to the protective layer 7 (hard layer 7a) when the separate film 6a is peeled off from the hard layer 7a of the protective layer 7 can be measured by heating h / 50 mm to 20 N / 50 mm in the pre-pressurized (p) state. The peel strength with respect to the protective layer 7 (hard layer 7a) is preferably 1 N / 50 mm to 10 N / 50 mm in a state after heating (h) / pressing (p) More preferably 4 N / 50 mm.

The surface roughness and the kind / amount of the release agent due to the irregularities 61 (the convex portions 61a and the concave portions 61b) of the separate film 6a formed through the mat working are changed in the manufacturing steps according to the purpose of use, The width of the adhesive strength (peel strength) of the separate film 6a to the protective layer 7 can be increased, and the control (adjustment) of the adhesive strength can be facilitated.

After the adhesive 8a 'is sufficiently adhered to the non-edge portion 3c and the insulating film 4 of the ground circuit 3b, as shown in Fig. 1 (b), the shielded flexible printed wiring board 10 1 (c), in which the concave and convex portions 71 are formed on the surface of the hard layer 7a when the separate film 6a of the shield film 1 is taken out together with the release layer 6b, The shield FPC 10 'shown in FIG.

Since the shield film 1 is thicker than the shield film body 9 by the thickness of the separate film 6a as shown in Fig. 2 (a), it can be easily punched to a predetermined size and cut neatly, 5) is also easy to align. In addition, since the cushioning effect is increased and the pressure is smoothly transmitted by the separate film 6a, the adhesive 8a 'can easily flow into the insulation removal part 4a. Therefore, the adhesive 8a 'is sufficiently adhered to the surface of the non-edge portion 3c of the ground circuit 3b, thereby improving the connection conductivity. Further, if the separate film 6a is peeled off together with the release layer 6b, a thin and flexible shield FPC 10 'can easily be obtained. In addition, the shield film 1 may be used for a rigid wiring board.

Both the base film 2 and the insulating film 4 are made of engineering plastics. Examples of the resin include resins such as polypropylene, crosslinked polyethylene, polyester, polybenzimidazole, polyimide, polyimideamide, polyetherimide and polyphenylene sulfide (PPS). In the case where heat resistance is not required to be high, a low-cost polyester film is preferable, a polyphenylene sulfide film is required when flame retardancy is required, and a polyimide film is required when higher heat resistance is required.

An engineering plastic such as the base film 2, the insulating film 4 and the protective layer 7 is also used for the separate film 6a, but since it is removed during the manufacturing process, a low cost polyester film is preferable. The release layer 6b can be formed by forming a silicon coating by a known method.

The adhesive layer 8a is an adhesive resin and may be a thermoplastic resin such as a polystyrene type, a vinyl acetate type, a polyester type, a polyethylene type, a polypropylene type, a polyamide type, a rubber type or an acrylic type, a phenol type, Melamine-based, and alkyd-based thermosetting resins. It is also possible to use a conductive adhesive obtained by mixing electrically conductive fillers such as metals and carbon with these adhesive resins to impart conductivity. By using the conductive adhesive in this way, the ground circuit 3b and the metal layer 8b can be electrically connected reliably. In addition, an anisotropic conductive adhesive having a reduced amount of conductive filler with a conductive adhesive may be used. When the anisotropic conductive adhesive is used as the conductive adhesive in this manner, the conductive film becomes thinner than the isotropic conductive adhesive and the amount of the conductive filler is reduced, so that it is possible to have excellent flexibility. An isotropic conductive adhesive may also be used as the conductive adhesive. When the isotropic conductive adhesive is used as the conductive adhesive in this way, it is possible to provide the ground connection for the ground circuit 3b and the like and to provide the electromagnetic wave shielding effect only by having the conductive adhesive layer using the isotropic conductive adhesive. When heat resistance is not particularly required, a polyester thermoplastic resin that is not restricted by storage conditions is preferable. When heat resistance or more excellent flexibility is required, the reliability after formation of the electromagnetic wave shield layer 8 is high Epoxy thermosetting resins are preferable. It goes without saying that in any case, the flow down (resin flow) at the time of heating / pressurization is preferably small.

In the above embodiment, the electromagnetic wave shielding layer 8 is composed of the metal layer 8b and the adhesive layer 8a. However, when the isotropic conductive adhesive is used for the adhesive layer 8a as described above, the metal layer 8b is omitted .

As the conductive filler, a silver-coated copper filler silver-plated with carbon, silver, copper, nickel, solder, aluminum and copper powder, or a filler in which a metal plating is applied to resin balls or glass beads, or a mixture of these fillers is used. It is preferable to use a silver-coated copper filler or nickel which is relatively inexpensive, has excellent conductivity, and is highly reliable, because silver is expensive, copper is lacking in heat resistance reliability, aluminum is inferior in humidity resistance reliability, and solder is difficult to obtain sufficient conductivity .

The mixing ratio of the conductive filler such as a metal filler and the adhesive resin also depends on the shape of the filler. In the case of the silver-coated copper filler, 10 to 400 parts by weight is preferable for 100 parts by weight of the adhesive resin, More preferably 150 parts by weight. If it exceeds 400 parts by weight, the adhesion to the ground circuit (copper foil) 3b is deteriorated and the flexibility of the shield FPC 10 'deteriorates. If it is less than 10 parts by weight, the conductivity is significantly lowered. The nickel filler is preferably blended in an amount of 40 to 400 parts by weight based on 100 parts by weight of the adhesive resin, more preferably 100 to 350 parts by weight. If it exceeds 400 parts by weight, the adhesion to the ground circuit (copper foil) 3b is deteriorated and the flexibility of the shield FPC 10 'deteriorates. If the amount is less than 40 parts by weight, the conductivity is significantly lowered. The shape of the conductive filler such as a metal filler can be any of spherical shape, needle shape, fiber shape, flake shape, and resin shape.

The thickness of the adhesive layer 8a is about 3 占 퐉 to 25 占 퐉 when the conductive filler such as a metal filler is mixed as described above, and 1 占 퐉 to 10 占 퐉 when the conductive filler is not mixed. As a result, the electromagnetic wave shielding layer 8 can be thinned, and a thin shield FPC 10 'can be formed.

Examples of the metal material for forming the metal layer 8b include aluminum, copper, silver and gold. The metal material can be appropriately selected according to the required shielding characteristics, but copper has a problem of being easily oxidized when it comes into contact with the atmosphere, and since gold is expensive, low-priced aluminum or highly reliable silver is preferable. The film thickness can be appropriately selected according to the required shielding property and flexibility, but is preferably 0.01 to 1.0 mu m in general. If it is less than 0.01 탆, the shielding effect becomes insufficient. Conversely, if it exceeds 1.0 탆, the flexibility becomes poor. Examples of the method for forming the metal layer 8b include vacuum deposition, sputtering, CVD, metal organic (MO) plating, and the like. Vacuum deposition is preferable in view of mass productivity, and a stable metal thin film can be obtained at low cost. The metal layer is not limited to a metal thin film, and a metal foil may be used.

The shield film 1 'shown in Fig. 2 (b) has an electromagnetic wave shielding layer 8' made of only an adhesive layer 8a formed of a conductive adhesive mixed with a conductive filler on one surface of the protective layer 7, Is different from the embodiment of Fig. 2 (a) in that the body 9 'is formed. Since the metal layer 8b has a higher conductivity than the adhesive layer 8a, when the metal layer 8b is provided as shown in Fig. 2 (a), it is not necessary to use an isotropic conductive adhesive, can do. In addition, the structure of the electromagnetic wave shield layer 8 is not limited to this, and it is preferable that the electromagnetic shield layer 8 has good conductivity and flexibility.

4 is a cross-sectional view of the shield FPC manufactured as described above. The shield FPC according to the present invention includes a shield film main body 9 in which an electromagnetic wave shield layer 8 'is formed only of an adhesive layer 8a made of a conductive adhesive agent as shown in FIG. 2 (b) (9 '). The materials and the forming methods of the shield film main body 9 may also include those described above.

Furthermore, the present invention is not limited to the single-sided shield, but may include the double-sided shield as shown in Figs. 4 (a) and 4 (b). The base film 2 'of the double-sided shield FPC 10A shown in Fig. 4A has a structure in which the insulating film 4 and the base film 2b are formed on the ground circuit 3b so that the adhesive layer 8a is connected to the ground circuit 3b. The insulating layer 4a and the insulating layer 2a 'are provided on the side of the substrate 2' and connected to the adhesive layer 8a on the upper and lower non-edge portions 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 the base film 5'.

The double-sided shield FPC 10B shown in Fig. 4B has the insulating film 4 and the insulating film 4a on the upper and lower sides of the ground circuit 3b and the base film 2 ' The ground circuit 3b is formed in the ground circuit 3b to form the ground circuit 3b 'and the adhesive layer 8a is formed in the through hole 3d' from both sides, And joins at the interface (s). The ground circuit 3b 'is connected to the adhesive layer 8a at the non-edge portion 3c of the upper surface and the inner surface 3c' of the through hole. Here, the base film 2 ', the printed circuit 3' (the signal circuit 3a 'and the ground circuit 3b') and the insulating film 4 constitute the gas film 5 ''.

[Example]

Next, results of the evaluation test conducted on the examples of the present invention will be described together with comparative examples.

(About the Psalms)

The shielding film 1 (the separator film 6a, the release layer 6b, the protective layer 7, the electromagnetic shield layer 8, and the like) having the characteristics described in Comparative Examples 1 and 2 and Examples 1 to 18 shown in Fig. 6 ) (Conductive adhesive layer 8a, metal layer 8b)) is used. In addition, each of the specimens is of a rectangular shape having a length of 200 mm and a width of 50 mm.

PET of the separate film 6a of Examples 1 to 18 was subjected to a matting process, Examples 1 to 12 were sand mats, Examples 13 and 16 were etching mats, Examples 14 and 17 were coating mats , Examples 15 and 18 were kneading mats. The PET of the separate films 6a of Comparative Examples 1 and 2 is a clear type in which no matting is performed.

The surface roughness (Ra (μm)) of Comparative Examples 1 and 2 and Examples 1 to 18 was measured by using a contact-type surface roughness meter. This is a method of measuring the illuminance of an object surface by measuring the movement of the needle when the needle moves up and down according to the irregularities of the object surface by overlapping the surface of the object with the probe.

Melamine releasing agent (Type A) was used in Comparative Example 1, Examples 1 to 8 and Examples 13 to 15, and Comparative Example 2, Examples 9 to 12 and Example 16 were used as the types of releasing layer 6b. To 18, an acrylic release agent (type B) was used, and the adhesion amounts were unified to 1.2 g / m ² respectively. As a method for measuring the adhesion amount of the release layer, first, the solid content concentration of the release agent is measured using an infrared moisture meter. Then, after coating the release agent, the amount of release agent is divided by the number of processed m ² to determine the wet adhesion amount. Then, the dry adhesion amount is determined from the wet adhesion amount and the solid content concentration of the release agent, and this dry adhesion amount is used as the adhesion amount of the release agent in this test.

(1) Peeling test of the separate film for the protective layer

(Test Methods)

In the peeling strength measurement before pressing (heating / pressing), a double-faced tape was stuck on the surface of the conductive adhesive layer 8a of the shielding film 1 according to Comparative Examples 1 and 2 and Examples 1 to 18, (PFT-50S peel strength tester) to the base of the tester (PALMEK company, PFT-50S peel strength tester) to fix the shield film (1). 7, the end portion of the separate film 6a of the shield film 1 is set on the chuck of the tester, and the peel strength of the separate film 6a with respect to the protective layer 7 is measured. Here, as shown in Fig. 7, the peeling angle was 170 degrees, and the peeling speed of the separate film 6a by the chuck was 1000 mm / min. The number of tests was performed five times, and the average of the minimum values of the peel strength values obtained by each test was calculated as the peel strength value (N / 50 mm).

On the other hand, in the peeling strength measurement after press (heating / pressing), the surfaces of the conductive adhesive layer 8a of the shield film 1 according to Comparative Examples 1 and 2 and Examples 1 to 18 were bonded to the polyimide surface and the copper foil surface Is thermally bonded to the polyimide side of the copper-clad laminate with a press machine. At this time, it is preferable that the conditions of the thermocompression of the press machine are 2 to 5 MPa in pressure, 140 to 180 ° C in temperature, and 3 to 60 minutes in time. In this measurement, the temperature was set to 170 占 폚, the pressure was applied at 0.5 MPa for 60 seconds, and then the pressure was applied at 3.0 MPa for 180 seconds.

Then, a double-sided tape was affixed to the copper foil side of the copper-clad laminate obtained by thermally pressing the shield film 1, and one side of the double-side tape was adhered to a pedestal of a tester (PALMEK PFT-50S peel strength tester) To fix the shield film (1). Thereafter, the peel strength value (N / 50 mm) is calculated in the same manner as in the test method described in the measurement of the peel strength before press.

(2) Evaluation method

The separation test evaluation method of the separate film for the protective layer will be described. In the separate film peeling test, when the peeling strength before pressing is less than 1N / 50 mm, the evaluation result is judged as "X". When the peel strength value before pressing is 1 to 20 N / 50 mm and the peel strength value after pressing is 1 to 10 N / 50 mm, the evaluation result is judged to be? (Circle). When the peel strength value is smaller than 1N / 50 mm, the separating film is peeled from the protective layer when the film is dipped in the chemical solution, and the peel strength value If the value is larger than 20 N / 50 mm, the adhesive strength of the separate film to the protective layer is too strong, and the protective film is peeled off to the protective layer when the separate film is peeled off. When the peel strength value is smaller than 1N / 50 mm, the separator film is naturally peeled off from the protective layer after pressing, and the peel strength value after pressing is 1 to 10 N / Is larger than 10 N / 50 mm, the workability is deteriorated when the separator film is peeled off from the protective layer by a person or a manufacturing apparatus (the separator film can not be smoothly peeled off without wasting a force when peeling the separator film from the protective layer) . Further, in addition to the evaluation condition of "O", in the shield film after pressing, if the peel strength value after pressing is 1 to 4 N / 50 mm, the separator film can be peeled more smoothly and the evaluation result is judged as "◎ (double circle)" .

Test results and judgment according to Comparative Examples 1 and 2 and Examples 1 to 18 described above are shown in Fig.

6, the shielding films 1 of Comparative Examples 1 and 2 using the clear type of PET that was not subjected to the matting treatment had a peel strength of 1 N before pressing and 1 N after pressing The separator film 6a is peeled off from the protective layer 7 when the type of the releasing agent is changed (the melamine releasing agent in Comparative Example 1, and the acrylic releasing agent in Comparative Example 2) (Examples 1 to 12 are sand mats, Examples 13 and 16 are etching mats, Example 14 and Example (Examples 14 and 16) The shielding film 1 of Examples 1 to 18 had a peel strength before press of 1 to 20 N / 50 mm and a peel strength after pressing of 1 to 10 N / 50 mm Because of this, (6a) was immersed in a chemical solution of a melamine releasing agent, Examples 9 to 12 and Examples 16 to 18 were changed to a different type of release agent (Examples 1 to 8 and Examples 13 to 15, Examples 9 to 12 and Examples 16 to 18) Is not peeled off from the protective layer (7). In other words, it can be seen that the peeling strength can not be controlled even if the type of the release agent is applied to the separate film 6a which is not subjected to the matte processing, and the chemical solution is intruded.

Further, as apparent from the peel strength values of Examples 1 to 8, the roughness of the matte working was changed from 1.000 m? 0.853 m? 0.679 m? 0.489 m? 0.352 m? 0.308 m? 0.253 m? (After press: 9.92N / 50mm)? Press: 9.48N / 50mm (after press: 5.67N / 50mm)? Press: 7.12N / 50mm (after press: 4.89N / 50 mm (after press: 2.78 N / 50 mm) → press: 2.97 N / 50 mm (after press: 3.50 N / 50 mm) / 50 mm), the pressing force is 1.55 N / 50 mm (after pressing: 1.15 N / 50 mm), and the pressing force is 1.12 N / 50 mm (after pressing: 1.00 N / 50 mm). Thus, it can be seen that the peel strength can be controlled by changing the roughness of the matte working. This is also true in the results of Examples 9 to 12 in which the type of the releasing agent is changed (the peeling strength value becomes smaller as the roughness value of the matte working is changed little).

Examples 1 to 8 using a release agent of a melamine releasing agent and Examples 9 to 12 using an acrylic release agent as a releasing agent show that when an acrylic release agent is used as a releasing agent, the peeling strength value before the pressing as compared with the case of using a melamine releasing agent as a releasing agent And the value of the peel strength after pressing becomes high. In comparison with Example 13 (etching mat, surface roughness 0.418 mu m, melamine releasing agent) and Example 16 (etching mat, surface roughness 0.418 mu m, acrylic releasing agent), Example 14 (coating mat, surface roughness 0.362 mu m, melamine releasing agent (Kneading mat, surface roughness of 0.245 mu m, melamine releasing agent) and Example 18 (kneading mat, surface roughness of 0.245 mu m, acrylic rubbers) and Comparative Example 17 (coating mat, surface roughness of 0.362 mu m, acrylic release agent) Release agent), it can be seen that, in the case of using an acrylic release agent as a releasing agent, the peeling strength value before pressing and the peeling strength value after pressing are higher than in the case of using a melamine releasing agent as a releasing agent. Thus, it can be seen that the peel strength value can also be controlled by changing the type of the peeling agent.

In Examples 1 to 18, when the range of the surface roughness is in the range of 0.2 占 퐉 to 1 占 퐉, the evaluation result is determined to be?. This is because if the surface roughness is smaller than 0.2 m, irregularities are not formed on the surface of the protective layer (hard layer) such that the anchor effect is exerted on the surface of the protective layer (hard layer), and the peel strength of the separate film can not be controlled. If the value is larger than 1.0 m, an anchor effect due to the irregularities on the surface of the protective layer (hard layer) largely acts (the adhesive strength becomes strong), and the protective film is peeled off to the protective layer.

The shield film 1 according to Examples 1 to 18 can peel off the protective film itself without peeling off the protective film itself when peeling the separate film 6a from the protective layer 7, .

In Examples 4 to 8 and Examples 12 to 18, the evaluation result was determined to be?. As a result, it can be seen that when the peel strength value after pressing is between 1 and 4 N / 50 mm, the separate film can be more smoothly peeled off when peeling the separate film from the protective layer.

As described above, the shield film 1 of the present embodiment has the resin layer 6b interposed between the surface of the separate film 6a on which the concave-convex portion 61 is formed and the concavo- The protective layer 7 is formed by further coating the hard layer 7a with the electromagnetic wave shielding layer 8 and separating the separate film 6a from the protective layer 7, ) Is 0.2 mu m to 1.0 mu m. The concavo-convex portion 61 on the surface of the separate film 6a and the concavo-convex portion 6b on the surface of the separate film 6a are bonded to the protective layer 7 with the release layer 6b interposed therebetween, Due to the anchor effect of the protrusions 71 on the surface of the protective layer 7 (hard layer 7a) having the surface roughness (Ra) of 0.2 to 1.0 μm formed by transfer of the protective film 61, The separator film 6a can be prevented from peeling off from the protective layer 7 because the chemical solution does not enter between the protective layer 7 and the separate film 6a when the protective film 7 is immersed in the protective layer 7, The adhesion of the separate film 6a to the separator film 7 can be enhanced. The protective layer 7 having a surface roughness (Ra) of 0.2 mu m to 1.0 mu m formed by transferring the concave-convex portion 61 of the surface of the separate film 6a and the convexo-concave portion 61 of the surface of the separate film 6a Since the releasing agent applied to the separate film 6a having the concave and convex portions 61 is naturally dispersed in the process of applying the releasing agent to the separate film 6a by providing the convex and concave portions 71 on the surface of the separating film 6a, The release layer 6b in a substantially uniformly dispersed state can be formed. Thereby, the adhesive property of the separate film 6a to the protective layer 7 can be improved to such an extent that the protective layer 7 itself is not torn due to too great adhesive force when the separate film 6a is peeled from the protective layer 7 . Since the adhesive strength of the separate film 6a to the protective layer 7 can be appropriately controlled as described above, it is possible to prevent defects caused by adhesion with too large adhesive force or too small adhesive force.

The shield film 1 of the present embodiment is such that the peel strength of the separate film 6a with respect to the protective layer 7 is in the range of 1 N / 50 mm to 20 N / 50 mm. According to this, it is possible to make the adhesion of the separate film 6a to the protective layer 7 more optimal.

The shield film 1 of the present embodiment has a peel strength with respect to the protective layer 7 of the separate film 6a after heating / pressing the shield film 1 to the base film 5 of 1 N / 50 mm to 10 N / 50 mm. According to this, it is possible to make the adhesion of the separate film 6a to the protective layer 7 more optimal.

The shield film 1 of the present embodiment can electrically connect the ground circuit 3b and the electromagnetic wave shielding layer 8 securely because the electromagnetic wave shielding layer 8 includes the conductive adhesive layer 8a.

The electromagnetic shielding layer 8 further includes the metal layer 8b and the anisotropic conductive adhesive agent is used for the conductive adhesive agent layer 8a to reduce the amount of the conductive filler, You can have sex.

The shield film 1 according to the present embodiment can be used for ground connection to the ground circuit 3b only by providing the conductive adhesive layer 8a by using an isotropic conductive adhesive agent for the conductive adhesive agent layer 8a At the same time, electromagnetic shielding effect can be obtained.

The present embodiment is characterized in that the corresponding concave and convex portions 61 of the separate film 6a having the concave and convex portions 61 formed on the entire one surface thereof are formed on at least one surface of the base film 5 including the printed circuit 3 of one or more layers, A shielding flexible printed wiring board 10 having a shield film 1 on which a protective layer 7 is formed by coating a resin with a release layer 6b interposed therebetween and a further electromagnetic shield layer 8 is formed , The surface roughness Ra of the protective layer 7 (hard layer 7a) when the separate film 6a is peeled off from the protective layer 7 is in the range of 0.2 to 1.0 占 퐉. According to this, the shielding flexible printed wiring board 10 having the electromagnetic wave shielding layer 8 and the protective layer 7 on one side of the base film 5 can secure the adhesive force of the separate film 6a to the protective layer 7 It is possible to prevent defects caused by adhesion with too large adhesive force or too small adhesive force.

The shielded flexible printed wiring board 10 of the present embodiment can have excellent flexibility because the base film 5 including the printed circuit 3 is formed of a flexible printed wiring board.

The shielded flexible printed wiring board 10 according to the present embodiment is a shielded flexible printed wiring board having flexibility and excellent insertion property because the gas film 5 including the printed circuit 3 can be a TAB tape for a tape carrier package 10) can be obtained.

The method of manufacturing the shield flexible printed circuit board 10 according to the present embodiment is characterized in that at least a part of the surface of the separate film 6a on which the concave- The shield film 1 obtained by laminating the release layer 6b, the protective layer 7 and the electromagnetic wave shielding layer 8 is mounted on at least one surface of the base film 5 including the printed circuit 3 of one or more layers, The protective film (6a) is peeled off from the protective layer (7) after heating / pressing the shield film (1) and the base film (5) 7). According to the above method, since the adhesive strength of the separate film 6a to the protective layer 7 can be appropriately controlled, it is possible to prevent defects caused by adhesion with too large adhesive force or too small adhesive force.

1, 1 'shield film
2, 2 'base film
2a 'Insulation Rejection
3, 3 'printed circuit
3a, 3a '
3b and 3b '
3c, 3c '
3d 'through hole
4 insulating film
4a Insulation Rejection
5, 5 ', 5''gaseous films
6a Separate film
6b release layer
7 protective layer
7a hard layer
7b soft layer
8, 8 'electromagnetic wave shield layer
8a adhesive layer
8a 'Adhesive
8b metal layer
9, 9 'Shield film body
10 Shield Flexible Printed Circuit Board
10 'Shield FPC
10A Double-sided shield FPC
10B double-sided shield FPC
11 Metal foil
12 Adhesive resin layer
71 uneven portion
71a convection
71b
s interface

Claims (10)

In a shield film in which a protective layer is formed by coating a resin with a releasing agent interposed therebetween on a surface side where the concavo-convex portion is formed on the entire surface of the separate film,
The surface roughness (Ra) of the protective layer when the separate film is peeled from the protective layer is 0.2 占 퐉 to 1.0 占 퐉,
The peel strength of the separator film to the protective layer before the shield film is heated to the printed circuit board side while heating the shield film is 1 N / 50 mm to 20 N / 50 mm,
The peel strength of the separate film to the protective layer after the shield film is mounted on the printed wiring board and after the shield film is heated to the printed wiring board side is 1 N / 50 mm to 10 N / 50 mm,
The peel strength of the separate film to the protective layer while the shield film is heated to the printed wiring board side while heating the shield film is higher than the peel strength of the separate film of the separate film after the shield film is pressed toward the printed wiring board while heating the shield film Wherein the shield film is larger than the shield film. The method according to claim 1,
Wherein the electromagnetic wave shield layer comprises a conductive adhesive layer. 3. The method of claim 2,
Wherein the electromagnetic wave shield layer further comprises a metal layer,
Wherein the conductive adhesive layer is composed of an anisotropic conductive adhesive layer. 3. The method of claim 2,
Wherein the conductive adhesive layer is composed of an isotropic conductive adhesive layer. 5. The method according to any one of claims 1 to 4,
And a concavo-convex portion is formed on the surface of the protective film on the side of the separate film by the transfer of the concavo-convex portion. 5. The method according to any one of claims 1 to 4,
Wherein the concave and convex portions of the separate film are formed by a mat treatment. On at least one surface of a substrate including one or more printed circuits,
There is provided a shield printed wiring board comprising a shield film on which a protective layer is formed by coating a resin with a releasing agent interposed therebetween and the electromagnetic wave shield layer is further formed on a surface of the separate film on which the concavo-
The surface roughness (Ra) of the protective layer when the separate film is peeled from the protective layer is 0.2 占 퐉 to 1.0 占 퐉,
The peel strength of the separator film to the protective layer before the shield film is heated to the printed circuit board side while heating the shield film is 1 N / 50 mm to 20 N / 50 mm,
The peel strength of the separate film to the protective layer after the shield film is mounted on the printed wiring board and after the shield film is heated to the printed wiring board side is 1 N / 50 mm to 10 N / 50 mm,
The peel strength of the separate film to the protective layer while the shield film is heated to the printed wiring board side while heating the shield film is higher than the peel strength of the separate film of the separate film after the shield film is pressed toward the printed wiring board while heating the shield film Of the shield printed wiring board. 8. The method of claim 7,
Wherein the substrate including the printed circuit is formed of a flexible printed wiring board. 8. The method of claim 7,
Wherein the substrate including the printed circuit is a TAB tape for a tape carrier package. A protective film is formed by coating a resin with a releasing agent interposed therebetween on the side where the concavo-convex part formed on the entire surface of the separator is formed, and the shield film on which the electromagnetic wave shield layer is further formed, A lamination step of laminating on one surface,
A heating / pressurizing step of pressing the shield film and the base body while heating them in the lamination direction after the laminating step, and
And a peeling step of peeling the separate film from the protective layer after the heating and pressing step,
The peel strength of the separate film before the heating / pressing step with respect to the protective layer is 1 N / 50 mm to 20 N / 50 mm,
The peel strength of the separate film after the heating and pressing process with respect to the protective layer is 1 N / 50 mm to 10 N / 50 mm,
The surface roughness (Ra) of the protective layer after the peeling step is 0.2 占 퐉 to 1.0 占 퐉,
The peel strength of the separate film to the protective layer before the shield film is heated to the printed wiring board side while heating the shield film is higher than the peel strength to the protective layer of the separate film after the shield film is pressed to the printed wiring board side while heating the shield film Wherein the shielded printed wiring board has a large size.

Images