JP2016009809A - Film for electromagnetic wave shield and electronic component mounting board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a film for electromagnetic wave shield, capable of effectively shielding even an electromagnetic wave in a high frequency band such as a GHz order while being lightened in weight and reduced in thickness; and an electronic component mounting board on which an electronic component is mounted, the electronic component being covered with an electromagnetic wave shielding layer using the film for electromagnetic wave shield.SOLUTION: A film for electromagnetic wave shield includes a base material layer and an electromagnetic wave shielding layer laminated on the base material layer. The electromagnetic wave shielding layer contains carbon fibers and a thermoplastic resin, and the content of the carbon fibers in the electromagnetic wave shielding layer is 30 mass% or more. The thermoplastic resin is preferably a thermoplastic elastomer.

Description

  The present invention relates to an electromagnetic wave shielding film and an electronic component mounting substrate.

  Conventionally, electronic components that are easily affected by electromagnetic waves, such as mobile phones and medical devices, exothermic electronic components such as semiconductor elements, various electronic components such as capacitors and coils, or these electronic components are mounted on a circuit board. In order to reduce the influence of noise caused by electromagnetic waves, an electromagnetic shielding film has been attached to the surface of the electronic devices.

  As such an electromagnetic wave shielding film, for example, a film having a base material layer made of an insulating material and a metal layer laminated on one or both surfaces of the base material layer has been developed (for example, Patent Documents). 1).

  However, as described in Patent Document 1, when the electromagnetic wave shielding film has a configuration having a metal layer, there is a problem that it is not possible to cope with the reduction in weight and thickness that has been increasingly demanded in recent years.

  Furthermore, as described above, the electronic devices to which the electromagnetic wave shielding film is attached are diversified, and accordingly, the frequency of electromagnetic waves, which are noises to be blocked, is diversified, and the electromagnetic wave shielding film is in the order of GHz. It is demanded that even the high frequency band can be effectively cut off.

JP 2006-156946 A

  An object of the present invention is to reduce the weight and thickness, and to effectively shield electromagnetic waves in a high frequency band as in the GHz order, and a substrate using such an electromagnetic wave shielding film. It is an object of the present invention to provide an electronic component mounting substrate in which an electronic component mounted thereon is covered with an electromagnetic wave shielding layer.

Such an object is achieved by the present invention described in the following (1) to (9).
(1) A film having an electromagnetic wave shielding layer,
The electromagnetic wave shielding layer contains carbon fiber and a thermoplastic resin, and the carbon fiber contains 30% by mass or more in the electromagnetic wave shielding layer.
(2) The electromagnetic shielding film according to (1), wherein the thermoplastic resin is a thermoplastic elastomer.
(3) The electromagnetic shielding film according to (1) or (2), wherein the thermoplastic elastomer is a styrene elastomer.
(4) The film for electromagnetic wave shield according to any one of (1) to (3), wherein the carbon fiber has an aspect ratio of 5 or more and 200 or less.
(5) Any one of (1) to (4), wherein the electromagnetic wave shielding layer has an electromagnetic wave shielding effect of 5 dB or more when measured using a microstripline method in an electromagnetic wave having a frequency of 0.2 to 1 GHz. Film for electromagnetic wave shielding as described in 2.
(6) The electromagnetic wave shielding layer according to any one of (1) to (5), wherein the electromagnetic wave shielding layer has an electromagnetic wave shielding effect of 7 dB or more when measured using the KEC method in an electromagnetic wave having a frequency of 0.2 to 1 GHz. Electromagnetic shielding film.
(7) The electromagnetic wave shielding film according to any one of (1) to (6), wherein the electromagnetic wave shielding layer has a thickness of 1 μm or more and 150 μm or less.
(8) The film for electromagnetic wave shielding according to any one of (1) to (7), comprising a base material layer laminated on one surface of the electromagnetic wave shielding layer.
(9) The film for electromagnetic wave shielding according to any one of (1) to (7), comprising an insulating layer laminated on one side of the electromagnetic wave shielding layer.
(10) The method according to any one of (1) to (7), further including a base material layer laminated on one side of the electromagnetic wave shielding layer, and further comprising an insulating layer laminated on a surface opposite to the base material layer. The film for electromagnetic wave shielding as described.
(11) The electromagnetic wave shielding film according to any one of (1) to (10), wherein the electromagnetic wave shielding film is used for covering irregularities on a substrate.
(11) An electronic component mounting substrate having a substrate, an electronic component mounted on the substrate, and an electromagnetic wave shielding layer that covers the substrate and the electronic component from the side of the substrate on which the electronic component is mounted. Because
The electronic component mounting substrate, wherein the electromagnetic wave shielding layer contains carbon fiber and a thermoplastic resin.

  According to the present invention, the electromagnetic wave shielding film comprises a base material layer, a carbon fiber, and an electromagnetic wave shielding layer containing a thermoplastic resin as a main material, thereby reducing the weight of the electromagnetic wave shielding layer. The thickness can be reduced, and electromagnetic waves in a high frequency band can be effectively blocked as in the GHz order.

It is a longitudinal cross-sectional view which shows 1st Embodiment of the film for electromagnetic wave shields of this invention. It is a longitudinal cross-sectional view for demonstrating the coating method of an electronic component using the electromagnetic wave shielding film shown in FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the film for electromagnetic wave shields of this invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the film for electromagnetic wave shields of this invention. It is a longitudinal cross-sectional view which shows 4th Embodiment of the film for electromagnetic wave shields of this invention. It is a longitudinal cross-sectional view which shows 5th Embodiment of the film for electromagnetic wave shields of this invention. It is a longitudinal cross-sectional view which shows 5th Embodiment of the film for electromagnetic wave shields of this invention. It is a longitudinal cross-sectional view which shows 5th Embodiment of the film for electromagnetic wave shields of this invention.

  Hereinafter, an electromagnetic wave shielding film and an electronic component mounting substrate of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  The electromagnetic wave shielding film of the present invention is characterized by comprising a carbon fiber and an electromagnetic wave shielding layer containing a thermoplastic resin.

According to such an electromagnetic wave shielding film, the electromagnetic wave shielding layer can be reduced in weight and thickness, and can effectively block electromagnetic waves in a high frequency band as in the GHz order.
<Electromagnetic wave shielding film>
<First Embodiment>
FIG. 1 is a longitudinal sectional view showing a first embodiment of an electromagnetic wave shielding film of the present invention. In the following description, for convenience of description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

  In the present embodiment, a case where the electromagnetic wave shielding film of the present invention is used to cover the unevenness 6 on the substrate 5 will be described as an example.

  As shown in FIG. 1, in this embodiment, the electromagnetic wave shielding film 100 includes a base material layer 1, an insulating layer 2, and an electromagnetic wave shielding layer 3, and the insulating layer 2 and the electromagnetic wave shielding layer 3 are The insulating layer 2 contacts the base material layer 1 from the lower surface (one surface) side of the base material layer 1 and is laminated in this order.

  The base material layer 1 includes a first layer 11, a second layer 13, and a third layer 12, which are arranged in this order from the upper surface (the other surface) side of the base material layer 1. Are stacked.

  In the following description, the electronic component 4 is mounted (placed) on the substrate 5, and the unevenness 6 including the convex portions 61 and the concave portions 62 is formed on the substrate 5 by mounting the electronic component 4. The case where 6 is covered with the electromagnetic wave shielding film 100 will be described. Examples of the electronic component 4 mounted on the substrate 5 include an LCD driver IC mounted on a flexible circuit board (FPC), an IC + capacitor around the touch panel, or an electronic circuit board (motherboard).

<Base material layer 1>
First, the base material layer 1 will be described.

  When the base material layer 1 covers the unevenness 6 by pressing the insulating layer 2 and the electromagnetic wave shielding layer 3 into the unevenness 6 on the substrate 5 using the electromagnetic wave shielding film 100 in the attaching step, the insulating layer 2 and the electromagnetic wave shielding layer 3 are pressed (embedded), and the insulating layer 2 and the electromagnetic wave shielding layer 3 function as a base material for improving the shape followability to the unevenness 6. Further, in the peeling step, the insulating layer 2 and the electromagnetic wave shielding layer 3 are pressed into the unevenness 6 and peeled from these.

  Moreover, it is preferable that the storage elastic modulus in 150 degreeC of this base material layer 1 is 2.0E + 05-2.0E + 08Pa, It is more preferable that it is 1.0E + 06-1.0E + 08Pa, 3.0E + 06-6.0E + 07Pa More preferably. By setting the storage elastic modulus within the above range, the step in the unevenness 6 provided on the substrate 5 is 500 μm or more, preferably a large step such as 1.0 to 3.0 mm, or the unevenness 6, the separation distance (pitch) between the convex portions 61 is 200 μm or less, preferably 100 μm to 150 μm, even if the separation distance is small. It can be pushed in reliably in the corresponding state.

  Moreover, it is preferable that the storage elastic modulus in 25 degreeC is 1.0E + 07-1.0E + 10Pa, and, as for the base material layer 1, it is more preferable that it is 5.0E + 08-5.0E + 09Pa. Thus, by setting the storage elastic modulus at room temperature (room temperature), that is, at 25 ° C., within the above range, the base material layer 1 is not liquid but solid before heating the electromagnetic shielding film 100. When the electromagnetic wave shielding film 100 is heated, it may be semi-solid (gel). Therefore, when the base material layer 1 (electromagnetic wave shielding film 100) is attached to the substrate 5, the base material layer 1 can be attached to the substrate 5 without causing wrinkles or the like, and cut to a specified size. In addition to improving the workability, the insulating layer 2 and the electromagnetic wave shielding layer 3 are surely pushed into the concave portion 62 of the concave and convex portion 6 with the base material layer 1 when pushed into the concave and convex portion 6 provided on the substrate 5. be able to. In addition, the base material layer 1 having such storage elastic modulus characteristics is such that at least the first layer 11 and the third layer 12 are made of a thermoplastic resin, and even after the heating of the electromagnetic wave shielding film 100 in the attaching step, The storage elastic modulus at 25 ° C. is preferably maintained within the above range. Thereby, the base material layer 1 can be easily peeled from the insulating layer 2 in the peeling step.

  Furthermore, when the storage elastic modulus at 120 ° C. of the base material layer 1 is A [Pa] and the storage elastic modulus at 150 ° C. of the base material layer 1 is B [Pa], 0.02 ≦ A / B ≦ 1. It is preferable to satisfy the relationship of 00, and it is more preferable to satisfy the relationship of 0.02 ≦ A / B ≦ 0.50. It can be said that the base material layer 1 satisfying such a relationship has a small range of change in the storage elastic modulus of the base material layer 1 due to the temperature change during the heating. Therefore, even if the temperature condition at the time of heating is changed, the range of change in the storage elastic modulus of the base material layer 1 due to this temperature change can be kept to the minimum necessary. The insulating layer 2 and the electromagnetic wave shielding layer 3 can be more reliably pushed into the concave portion 62 of the concave and convex portion 6 by the base material layer 1.

  Thus, by setting the storage elastic modulus at the time of heating of the base material layer 1 functioning as a base material for improving the shape followability to the unevenness 6 of the insulating layer 2 and the electromagnetic wave shielding layer 3 within the above range. When the unevenness 6 on the substrate 5 is covered using the electromagnetic wave shielding film 100, the insulating layer 2 and the electromagnetic wave shielding layer 3 can be reliably pushed in a state corresponding to the shape of the unevenness 6. As a result, since the substrate 5 provided with the unevenness 6 can be reliably covered with the electromagnetic wave shielding layer 3, the electromagnetic wave shielding (blocking) property to the substrate 5 provided with the unevenness 6 by the electromagnetic wave shielding layer 3 is provided. Will be improved.

  In addition, the storage elastic modulus in 25 degreeC, 120 degreeC, and 150 degreeC of each layer is the storage elastic modulus of each layer which should be measured, for example using a dynamic viscoelasticity measuring apparatus (the Seiko Instruments company make, "DMS6100"). Is measured from 25 to 200 ° C. in a tensile mode with a constant load of 49 mN at a heating rate of 5 ° C./min and a frequency of 1 Hz, and the storage elastic moduli at 25 ° C., 120 ° C. and 150 ° C. are respectively read. be able to.

  In the present embodiment, the base material layer 1 includes a first layer 11, a second layer 13, and a third layer 12, which are from the upper surface (the other surface) side of the base material layer 1. These layers are laminated in this order, and as described above, the types and thicknesses of these layers 11 to 13 can be pressed so that the insulating layer 2 and the electromagnetic wave shielding layer 3 can be pressed in accordance with the shape of the irregularities 6. Etc. are appropriately combined.

  Hereinafter, each of these layers 11 to 13 will be described.

  The first layer 11 is a pressing force possessed by a vacuum pressure laminator or the like when the insulating layer 2 and the electromagnetic wave shielding layer 3 are pushed into the unevenness 6 on the substrate 5 using, for example, a vacuum pressure laminator or the like in the pasting step. This is to provide a function of releasability with the part. Moreover, it is for propagating the pressing force from a pressing part to the 2nd layer 13 side.

  The constituent material of the first layer (first release layer) 11 is not particularly limited. For example, a resin such as syndiotactic polystyrene, polymethylpentene, polybutylene terephthalate, polypropylene, cyclic olefin polymer, and silicone. Materials. Among these, it is preferable to use syndiotactic polystyrene. Thus, since polystyrene can be provided with crystallinity by using what has a syndiotactic structure as polystyrene, the mold release from the apparatus of the 1st layer 11 originates in this. Properties, heat resistance and shape followability can be improved.

  When the syndiotactic polystyrene is used for the first layer 11, the content thereof is not particularly limited, but is preferably 60% by weight or more, more preferably 70% by weight or more and 95% by weight or less. Further, it is preferably 80% by weight or more and 90% by weight or less. When content of syndiotactic polystyrene is less than the said lower limit, there exists a possibility that the releasability of the 1st layer 11 may fall. Moreover, when content of syndiotactic polystyrene exceeds the said upper limit, there exists a possibility that the shape followability of the 1st layer 11 may become insufficient.

 The first layer 11 may be composed of only syndiotactic polystyrene. The first layer 11 may further contain a styrene elastomer, polyethylene, polypropylene, or the like in addition to the syndiotactic polystyrene.

  The thickness T (A) of the first layer 11 is not particularly limited, but is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 70 μm or less, and further preferably 20 μm or more and 50 μm or less. is there. When the thickness of the 1st layer 11 is less than the said lower limit, the 1st layer 11 may fracture | rupture and there exists a possibility that the release property may fall. Moreover, when the thickness of the 1st layer 11 exceeds the said upper limit, the shape followability of the base material layer 1 may fall, and there exists a possibility that the shape followability of the electromagnetic wave shielding layer 3 and the insulating layer 2 may fall.

 Moreover, it is preferable that the average linear expansion coefficient in 25-150 degreeC of the 1st layer 11 is 50-1000 [ppm / degrees C], and it is more preferable that it is 100-700 [ppm / degrees C]. By setting the average linear expansion coefficient of the first layer 11 within such a range, the first layer 11 has excellent stretchability when the electromagnetic wave shielding film 100 is heated. The shape followability with respect to the unevenness 6 of the layer 3 and the insulating layer 2 can be improved more reliably.

 In addition, the average linear expansion coefficient of each layer is, for example, a storage elastic modulus of each layer to be measured from 25 to 200 ° C., 49 mN using a thermomechanical analyzer (“TMASS6100” manufactured by Seiko Instruments Inc.). The average linear expansion coefficient at 25 ° C. to 150 ° C. can be obtained by measuring at a temperature rising rate of 5 ° C./min in a constant load tension mode.

 Furthermore, the surface tension of the first layer 11 is preferably 20 to 40 [mN / m], and more preferably 25 to 35 [mN / m]. The first layer 11 having a surface tension within such a range can be said to have excellent releasability, and the first layer 11 is peeled from the pressing portion after being pressed using a vacuum pressure laminator or the like. Can be made.

 The third layer 12 is formed by pressing the insulating layer 2 and the electromagnetic wave shielding layer 3 against the unevenness 6 on the substrate 5 using a vacuum pressure laminator or the like in the attaching step, and then in the peeling step. When the layer is peeled from the insulating layer 2, the base layer 1 is provided with a peelable function. Moreover, according to the uneven | corrugated shape on the board | substrate 5, it has the function of the tracking property which the 3rd layer 12 follows, and also has the function to propagate the pressing force from a press part on the insulating layer 2 side. is there.

 The constituent material of the third layer (second release layer) 12 is not particularly limited. For example, syndiotactic polystyrene, polymethylpentene, polybutylene terephthalate, polypropylene, cyclic olefin polymer, resin such as silicone Materials. Among these, it is preferable to use syndiotactic polystyrene. Thus, since polystyrene can be provided with crystallinity by using what has a syndiotactic structure as polystyrene, it originates in this, and with the insulating layer 2 of the 3rd layer 12 The mold releasability, as well as the heat resistance and shape followability can be improved.

 The content of the syndiotactic polystyrene in the third layer 12 is not particularly limited and may be composed only of syndiotactic polystyrene, but is preferably 60% by weight or more, and 70% by weight or more. 95% by weight or less, more preferably 80% by weight or more and 90% by weight or less. When content of syndiotactic polystyrene is less than the said lower limit, there exists a possibility that the mold release property of the 3rd layer 12 may fall. Moreover, when content of a syndiotactic polystyrene exceeds the said upper limit, there exists a possibility that the shape followability of the 3rd layer 12 may become insufficient.

 The third layer 12 may further contain a styrene elastomer, polyethylene, polypropylene, or the like in addition to the syndiotactic polystyrene. Further, the resin constituting the third layer 12 and the first layer 11 may be the same or different.

 The thickness T (B) of the third layer 12 is not particularly limited, but is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 70 μm or less, and further preferably 20 μm or more and 50 μm or less. is there. When the thickness of the third layer 12 is less than the lower limit, the heat resistance is insufficient, the heat resistance of the base material layer is insufficient in the thermocompression bonding process, deformation occurs, and the electromagnetic wave shielding layer and the insulating layer are deformed. There is a fear. Moreover, when the thickness of the 3rd layer 12 exceeds the said upper limit, the total thickness of the whole film for electromagnetic wave shielding becomes thick, there exists a possibility that workability | operativity, such as a cut, may fall, and it is not economical also in terms of cost. .

 The thicknesses of the third layer 12 and the first layer 11 may be the same or different.

  Moreover, it is preferable that the average linear expansion coefficient in 25-150 degreeC of the 3rd layer 12 is 50-1000 [ppm / degreeC], and it is more preferable that it is 100-700 [ppm / degreeC]. By setting the average linear expansion coefficient of the third layer 12 within this range, the third layer 12 has excellent stretchability when the electromagnetic wave shielding film 100 is heated. The shape followability of the layer 12 and the electromagnetic wave shielding layer 3 and the insulating layer 2 with respect to the irregularities 6 can be improved more reliably.

  Furthermore, the surface tension of the third layer 12 is preferably 20 to 40 [mN / m], and more preferably 25 to 35 [mN / m]. The third layer 12 having a surface tension within such a range can be said to have excellent releasability, and the base material layer 1 is peeled from the insulating layer 2 after being pushed in using a vacuum pressure laminator or the like. In doing so, the base material layer 1 can be reliably peeled off at the interface between the third layer 12 and the insulating layer 2.

 The second layer 13 is a third layer when the insulating layer 2 and the electromagnetic wave shielding layer 3 are pressed into the unevenness 6 on the substrate 5 using the base material layer 1 as a pressing base material in the attaching step. 12 has a cushioning function for pushing (embedding) 12 into the irregularities 6. Further, the second layer 13 has a function of causing the pushing force to uniformly act on the third layer 12 and further on the insulating layer 2 and the electromagnetic wave shielding layer 3 via the third layer 12. Thus, the insulating layer 2 and the electromagnetic wave shielding layer 3 can be pushed into the irregularities 6 with excellent sealing properties without generating voids between the electromagnetic wave shielding layer 3 and the irregularities 6.

  As a constituent material of the second layer (cushion layer) 13, for example, an α-olefin polymer such as polyethylene or polypropylene, ethylene, propylene, butene, pentene, hexene, methylpentene, or the like is included as a copolymer component. Engineering plastics resins such as α-olefin copolymer, polyethersulfone, polyphenylene sulfide and the like may be used, and these may be used alone or in combination. Among these, it is preferable to use an α-olefin copolymer. Specifically, a copolymer of α-olefin such as ethylene and (meth) acrylic acid ester, a copolymer of ethylene and vinyl acetate, a copolymer of ethylene and (meth) acrylic acid (EMMA), And a partial ion cross-linked product thereof. Since the α-olefin copolymer is excellent in shape followability and further excellent in flexibility as compared with the constituent material of the third layer 12, the second layer 13 made of the constituent material has the The cushion function for pushing (embedding) the third layer 12 into the unevenness 6 can be surely provided.

 The thickness T (C) of the second layer 13 is not particularly limited, but is preferably 10 μm or more and 100 μm or less, more preferably 20 μm or more and 80 μm or less, and further preferably 30 μm or more and 60 μm or less. is there. When the thickness of the second layer 13 is less than the lower limit value, the shape followability of the second layer 13 is insufficient, and the followability to the unevenness 6 may be insufficient in the thermocompression bonding step. Further, when the thickness of the second layer 13 exceeds the upper limit value, the resin from the second layer 13 is increased in the thermocompression bonding process, and adheres to the hot platen of the crimping apparatus, thereby reducing workability. There is a risk of doing.

 The average linear expansion coefficient of the second layer 13 at 25 to 150 ° C. is preferably 500 or more [ppm / ° C.], more preferably 1000 or more [ppm / ° C.]. By setting the average linear expansion coefficient of the second layer 13 within such a range, the second layer 13 can be expanded and contracted more excellently than the third layer 12 when the electromagnetic wave shielding film 100 is heated. It can be made easy to have a property. Therefore, the shape followability of the second layer 13 and the electromagnetic wave shielding layer 3 and the insulating layer 2 with respect to the irregularities 6 can be improved more reliably.

 In addition, it is easy to set the storage elastic modulus at 150 ° C. of the base material layer 1 within the range of 2.0E + 05 to 2.0E + 08 Pa by appropriately setting the average linear expansion coefficient of each layer 11 to 13 within the above-described range. Can be set to

The thickness T (A) of the first layer 11, the thickness T (B) of the third layer 12, and the thickness T (C) of the second layer 13 satisfy the following relational expression, for example. Preferably
0.05 <T (C) / (T (A) + T (B)) <10,
More preferably, the following relational expression is satisfied:
0.14 <T (C) / (T (A) + T (B)) <4,
More preferably, the following relational expression is satisfied:
0.3 <T (C) / (T (A) + T (B)) <1.5.

 When the thickness T (A) of the first layer 11, the thickness T (B) of the third layer 12, and the thickness T (C) of the second layer 13 satisfy the relational expression, the shape follows. More improved.

The total thickness T (F) of the base material layer 1 is not particularly limited, but is preferably 20 μm or more and 300 μm or less, more preferably 40 μm or more and 220 μm or less, and further preferably 70 μm or more and 160 μm or less. It is. When the whole thickness of the base material layer 1 is less than the said lower limit, the 1st layer 11 may fracture | rupture and there exists a possibility that the releasability of the base material layer 1 may fall. Moreover, when the whole thickness of the base material layer 1 exceeds the said upper limit, there exists a possibility that the shape followability of the base material layer 1 may fall and the shape followability of the electromagnetic wave shielding layer 3 and the insulating layer 2 may fall.
<Insulating layer 2>
Next, the insulating layer 2 will be described.

 In this embodiment, the insulating layer 2 is provided in contact with the base material layer 1 (third layer 12), and is laminated in the order of the insulating layer 2 and the electromagnetic wave shielding layer 3 from the base material layer 1 side. The electromagnetic wave shielding layer 3 comes into contact with the substrate 5 and the electronic component 4 by covering the unevenness 6 on the substrate 5 with the electromagnetic wave shielding film 100 including the insulating layer 2 and the electromagnetic wave shielding layer 3 laminated in this manner. The electromagnetic wave shielding layer 3 and the insulating layer 2 are coated in this order from the substrate 5 side.

 Thus, in the present embodiment, the insulating layer 2 covers the substrate 5 and the electronic component 4 via the electromagnetic wave shielding layer 3, whereby the substrate 5, the electronic component 4 and the electromagnetic wave shielding layer 3 are covered with the insulating layer. 2 to insulate from other members (such as electronic components) located on the opposite side of the substrate 5.

 Examples of the insulating layer 2 include a thermosetting insulating resin or a thermoplastic insulating resin (insulating film). Among these, it is preferable to use an insulating resin having thermoplasticity. Since the insulating resin having thermoplasticity is a film having excellent flexibility, the insulating layer 2 and the electromagnetic waves are formed on the unevenness 6 on the substrate 5 by using the base material layer 1 as a pressing base material in the attaching step. When the blocking layer 3 is pushed in, the insulating layer 2 can be made to reliably follow the shape of the irregularities 6. In addition, an insulating resin having thermoplasticity is particularly useful when repairing a substrate because it can be re-peeled from the substrate to be bonded when heated to its softening point temperature.

   Examples of the thermoplastic insulating resin include thermoplastic polyester, α-olefin, vinyl acetate, polyvinyl acetal, ethylene vinyl acetate, vinyl chloride, acrylic, polyamide, and cellulose. Among these, it is preferable to use thermoplastic polyesters and α-olefins because they are excellent in adhesion to the substrate, flexibility and chemical resistance.

 Furthermore, the insulating resin having thermoplasticity is a phenolic resin, a silicone resin, a urea resin, an acrylic resin, a polyester resin, a polyamide resin, as long as the performance such as heat resistance and flex resistance is not impaired. A polyimide resin or the like can be contained. In addition, in the insulating resin having thermoplasticity, as in the case of the conductive adhesive layer described later, a silane coupling agent, an antioxidant, a pigment, a dye, as long as the adhesiveness and solder reflow resistance are not deteriorated. You may add tackifying resin, a plasticizer, a ultraviolet absorber, an antifoamer, a leveling regulator, a filler, a flame retardant, etc.

 The thickness T (D) of the insulating layer 2 is not particularly limited, but is preferably 3 μm or more and 50 μm or less, more preferably 4 μm or more and 30 μm or less, and further preferably 5 μm or more and 20 μm or less. When the thickness of the insulating layer 2 is less than the lower limit value, the resistance to goby folds is insufficient, cracks are generated at the bent portions after thermocompression bonding to the projections and depressions 6, the film strength decreases, and the conductive adhesive layer It is difficult to play a role as an insulating support. If the upper limit is exceeded, shape followability may be insufficient. That is, by setting the thickness T (D) of the insulating layer 2 within the above range, the insulating layer 2 can be made more flexible, and the base material layer 1 can be used as a base for pushing in the attaching step. When the insulating layer 2 and the electromagnetic wave shielding layer 3 are pushed into the unevenness 6 on the substrate 5 by using as a material, the insulating layer 2 can be made to follow more reliably corresponding to the shape of the unevenness 6.

 Moreover, it is preferable that the average linear expansion coefficient in 25-150 degreeC of the insulating layer 2 is 50-1000 [ppm / degrees C], and it is more preferable that it is 100-700 [ppm / degrees C]. By setting the average linear expansion coefficient of the insulating layer 2 within this range, the insulating layer 2 has excellent stretchability when the electromagnetic wave shielding film 100 is heated. The shape following property with respect to the unevenness 6 of the electromagnetic wave shielding layer 3 can be improved more reliably.

In addition, as shown in FIGS. 1 and 2, the insulating layer 2 may be a laminated body of two or more layers obtained by laminating different ones of the above-described insulating films in addition to the one constituted by one layer. .
<Electromagnetic wave blocking layer 3>
Next, the electromagnetic wave blocking layer (blocking layer) 3 will be described.

  The electromagnetic wave shielding layer 3 includes an electronic component 4 provided on the substrate 5, and other electronic components located on the opposite side of the substrate 5 (electronic component 4) via the electromagnetic wave shielding layer 3. It has a function of shielding (shielding) electromagnetic waves generated from one side.

  Here, in general, in order to exert the function of blocking electromagnetic waves, a reflection layer that blocks (shields) the electromagnetic wave incident on the electromagnetic wave blocking layer and absorbs the electromagnetic wave incident on the electromagnetic wave blocking layer. Absorbing layers that are shielded (shielded) by the above are known.

 In such a reflection layer and an absorption layer, assuming that they have almost the same electromagnetic shielding properties, the absorption layer absorbs electromagnetic waves incident on the absorption layer and converts them into thermal energy. The electromagnetic wave is extinguished by this absorption. Therefore, from the standpoint that it is possible to reliably prevent the reflected electromagnetic wave, such as the reflective layer, from adversely affecting the other members that are not covered with the electromagnetic wave blocking layer. The layer is preferably composed of an absorbent layer.

  Therefore, the present inventor paid attention to an electromagnetic wave blocking layer containing a π-conjugated carbon material known as an electromagnetic wave blocking layer for blocking electromagnetic waves as a main material, and as a result of earnestly examining such an electromagnetic wave blocking layer, carbon fiber was used. Thus, it has been found that the electromagnetic wave shielding layer exerts the function as an absorbing layer without the electromagnetic wave shielding layer exerting the function as a reflective layer.

  In other words, when the electromagnetic wave blocking layer contains carbon fiber, the function as an absorbing layer can be exhibited accurately, and electromagnetic waves are effectively blocked by absorbing electromagnetic waves up to electromagnetic waves in the high frequency band as in the GHz order. The present invention has been found and the present invention has been completed.

  The carbon fiber may be PAN-based or pitch-based, but PAN-based is preferable from the viewpoint of conductivity with respect to the added amount. As a result, good shielding properties can be obtained.

  The aspect ratio of the carbon fiber is preferably 5 or more and 200 or less. Thereby, even an electromagnetic wave in a higher frequency band can be shielded more effectively.

  The carbon fiber preferably has an average fiber diameter of 5 μm or more and 30 μm or less.

  The length of such carbon fibers is preferably 25 μm or more and 6000 μm or less in average length.

  By setting the particle size and length of the carbon fiber within the above range, the aspect ratio of the carbon fiber can be easily set within the above range.

 Further, the content of the carbon fiber in the electromagnetic wave shielding layer 3 is preferably 30 or more and 90 or less, and more preferably 30 or more and 75 or less. Within the above range, the electromagnetic wave shielding property and the film property are maintained, which is preferable.

  Next, the binder resin will be described.

  The binder resin has a function of forming the electromagnetic wave shielding layer 3 into a film.

  Here, the binder resin used to form the electromagnetic wave shielding layer 3 includes a thermoplastic resin.

  Since the above-mentioned carbon fiber has a high aspect ratio, the shape stability of the electromagnetic wave shielding layer 3 is deteriorated when blended in a large amount so as to have an electromagnetic wave shielding property. Further, it becomes difficult to uniformly disperse the carbon fiber in the electromagnetic wave shielding layer 3, and it becomes difficult to make the function of the electromagnetic wave shielding layer 3 uniform in the layer.

  Here, by using an olefin resin as the thermoplastic resin, the shape stability of the electromagnetic wave shielding layer 3 can be expressed by the fluidity of the olefin resin.

  Although it does not specifically limit as an olefin resin, Polyethylene, a polypropylene, etc. are mentioned. Among these, polypropylene is particularly preferable. Thereby, shape stability and shape followability to unevenness can be expressed.

 In addition, by including a thermoplastic elastomer as the binder resin, it is possible to develop the shape stability and uniform function of the electromagnetic wave shielding layer 3 due to the fluidity and low elastic modulus of the thermoplastic elastomer.

  Although it does not specifically limit as a thermoplastic elastomer, A styrene-type elastomer, a polyester-type elastomer, an olefin-type elastomer, a vinyl chloride-type elastomer, a polyurethane-type elastomer, a polyamide-type elastomer etc. are mentioned. Of these, styrene-based elastomers are particularly preferable. Thereby, shape stability and the shape followability to an unevenness | corrugation can be expressed.

 As the binder resin, the thermoplastic resin is essential, but other resins may be used in combination. Although it does not specifically limit as other resin, An epoxy resin, a phenol resin, a polyester resin, a polyurethane resin, an acrylic resin, a melamine resin, a polyimide resin, a polyamideimide resin etc. can be used.

 Further, the content of the thermoplastic resin in the electromagnetic wave shielding layer 3 is preferably 20% by mass or more and 85% by mass or less, and more preferably 25% by mass or more and 70% by mass or less. Within the above range, the electromagnetic wave shielding property and the film property are maintained, which is preferable.

 The thickness T of the electromagnetic wave shielding layer 3 is not particularly limited, but is preferably 1 μm or more and 150 μm or less, more preferably 2 μm or more and 100 μm or less, and further preferably 3 μm or more and 80 μm or less. When the thickness of the electromagnetic wave shielding layer 3 is less than the lower limit value, depending on the constituent material of the electromagnetic wave shielding layer 3, there is a possibility of breaking at the end portion of the board mounted component. Moreover, when the thickness of the electromagnetic wave shielding layer 3 exceeds the upper limit, the shape following property may be insufficient depending on the constituent material of the electromagnetic wave shielding layer 3 or the like. Moreover, since the excellent electromagnetic wave shielding property can be exhibited even when the thickness T is within such a range, it is possible to reduce the thickness T of the electromagnetic wave shielding layer 3, and thus the insulating layer 2 and the electromagnetic wave on the substrate 5. The weight reduction of the electronic component mounting board on which the electronic component 4 covered with the blocking layer 3 is mounted can be realized.

 The electromagnetic wave shielding layer 3 as described above has an electromagnetic wave shielding property (absorbability) of 5 dB or more for shielding (shielding) an electromagnetic wave at a frequency of 0.2 to 1 GHz, measured using a microstrip line method (MSL method). Preferably, it is 6 dB or more, more preferably 7 dB or more. Here, in the MSL method, the electromagnetic wave shielding property for blocking electromagnetic waves is measured as a value representing the absorbability (absorbing ability) blocking mainly by absorbing electromagnetic waves from the characteristics of the measurement method described below. Therefore, the electromagnetic wave shielding layer 3 having the electromagnetic wave shielding property (absorbing property) within the above range exhibits excellent electromagnetic wave shielding property by shielding (shielding) by absorbing the electromagnetic wave incident on the electromagnetic wave shielding layer 3. It can be said that the electromagnetic wave blocking layer (absorbing layer) 3 is capable of blocking even high frequency electromagnetic waves as in the GHz order.

 The measurement using the MSL method is, for example, measuring the reflection component S11 and the transmission component S21 using a microstrip line having an impedance of 50Ω and a network analyzer in accordance with IEC standard 62333-2. The electromagnetic wave shielding property (absorbability) can be obtained by using the following formula (1) and the following formula (2).

Loss rate (P (loss) / P (in)) = 1− (S112 + S212) / 1 (1)
Electromagnetic shielding property (transmission attenuation factor) = − 10 · log [10 ^ (S21 / 10) / {1-10 ^ (S11 / 10)}] (2)
Furthermore, the electromagnetic wave shielding layer 3 has an electromagnetic wave shielding property (absorbing property + reflective property) for shielding (shielding) electromagnetic waves at a frequency of 0.2 to 1 GHz measured using the KEC method developed at the Kansai Electronics Industry Promotion Center. It is preferably 7 dB or more, more preferably 7.5 dB or more, and even more preferably 8 dB or more. Here, in the KEC method, the electromagnetic wave shielding property for blocking electromagnetic waves is based on the characteristics of the measuring method described below, and absorbs (absorbs) the light by absorbing the electromagnetic wave and reflects by blocking the electromagnetic wave. It is measured as a value obtained by adding the property (reflectivity). Therefore, the electromagnetic wave shielding property (absorbing property) measured using the MSL method is within the above range, and the electromagnetic wave shielding property (absorbing property + reflecting property) measured using the KEC method is within the above range. For example, it can be said that the electromagnetic wave shielding layer 3 exhibits excellent electromagnetic shielding properties by absorbing and reflecting the electromagnetic wave incident on the electromagnetic wave shielding layer 3 and blocking (shielding) it. Even electromagnetic waves can be reliably blocked.

 The KEC method is a method for evaluating the shielding effect of electromagnetic waves generated in the near field separately for electric and magnetic fields, and measurement using this method is based on electromagnetic waves transmitted from a transmission antenna (transmission jig). Can be received by a receiving antenna (receiving jig) through an electromagnetic wave shielding layer 3 (measurement sample) in the form of a sheet. In such a KEC method, an electromagnetic wave shielding layer is formed in the receiving antenna. The electromagnetic wave passing through (transmitting) 3 is measured, that is, how much the transmitted electromagnetic wave (signal) is attenuated by the electromagnetic wave blocking layer 3 on the receiving antenna side, so that the electromagnetic wave is blocked (shielded). The electromagnetic wave shielding property is obtained in a state where both the reflectivity for reflecting electromagnetic waves and the absorbency for absorbing electromagnetic waves are added together.

 Moreover, it is preferable that the storage elastic modulus in 150 degreeC of the electromagnetic wave shielding layer 3 is 1.0E + 05-1.0E + 09Pa, and it is more preferable that it is 5.0E + 05-5.0E + 08Pa. By setting the storage elastic modulus within such a range, in the pasting step, after heating the electromagnetic wave shielding film 100, the insulating layer 2 and the electromagnetic wave are formed on the unevenness 6 on the substrate 5 by pressing force from the base material layer 1. By pressing the blocking layer 3, the electromagnetic wave blocking layer 3 can be deformed corresponding to the shape of the unevenness 6 according to the pressing force from the base material layer 1 when covering the unevenness 6. That is, the shape followability of the electromagnetic wave shielding layer 3 with respect to the unevenness 6 can be improved.

 Further, the electromagnetic wave shielding film 100 has shape conformability when thermocompression bonding is performed on the unevenness 6 formed by mounting the electronic component 4 on the substrate 5 at a temperature of 150 ° C., a pressure of 2 MPa, and a time of 5 minutes. The thickness is preferably 500 μm or more, more preferably 800 μm or more, and still more preferably 1000 μm or more. That is, the electromagnetic wave shielding film 100 can preferably cover the unevenness 6 having a height of 500 μm or more, which is the difference in height between the upper surface of the convex portion 61 and the upper surface of the concave portion 62, and can cover a thickness of 800 μm or more. More preferably, it is more preferable that a film having a thickness of 1000 μm or more can be coated. Thus, it can be said that the electromagnetic wave shielding film 100 that can be covered even with the unevenness 6 having a high height (a large level difference) has excellent shape followability, and the insulating layer 2 and the electromagnetic wave shielding layer 3 It is possible to cover the unevenness 6 with an excellent filling rate.

 The shape following property can be obtained as follows.

 That is, first, a printed wiring board having a width of 0.2 mm and a groove of each necessary step is formed in a grid pattern at intervals of 0.2 mm on a printed wiring board (motherboard) having a length of 100 mm × width of 100 mm × height of 2 mm Get. Then, the film for electromagnetic wave shielding is pressure-bonded to the printed wiring board under a condition of 150 ° C. × 2 MPa × 5 minutes using a vacuum pressurizing laminator, and attached to the printed wiring board. After pasting, the base material layer is peeled off from the electromagnetic wave shielding film, and it is determined whether or not there is a gap between the blocking layer and insulating layer stuck on the printed wiring board and the groove on the printed wiring board. In addition, it is evaluated by observing with a microscope or a microscope whether there exists a space | gap.

<Method of coating electronic parts>
Next, a method for coating an electronic component will be described.

 The electronic component covering method according to the present embodiment includes an attaching step of attaching the electromagnetic wave shielding film to the unevenness on the substrate so that the electromagnetic wave shielding layer or the insulating layer and the electronic component adhere to each other. And a peeling step of peeling the base material layer.

 FIG. 2 is a longitudinal sectional view for explaining a method of coating an electronic component using the electromagnetic wave shielding film shown in FIG.

 Hereafter, each process of the coating method of an electronic component is demonstrated sequentially.

(Attaching process)
The affixing step is a step of affixing the electromagnetic wave shielding film 100 to the unevenness 6 provided on the substrate 5, for example, as shown in FIG.

 The method for attaching is not particularly limited, and examples thereof include vacuum / pressure forming.

 Vacuum / pressure forming is, for example, a method of covering the irregularities 6 on the substrate 5 with the electromagnetic wave shielding film 100 using a vacuum pressurizing laminator. First, the substrate 5 is placed in a closed space that can be in a vacuum atmosphere. The substrate 5 and the electromagnetic wave shielding film 100 are set in an overlapped state so that the surface on which the unevenness 6 is formed and the surface on the insulating layer 2 side of the electromagnetic wave shielding film 100 face each other, and thereafter In the heating process, the closed space is placed in a vacuum atmosphere and then pressurized so that the electromagnetic wave shielding film 100 and the substrate 5 approach each other uniformly from the electromagnetic wave shielding film 100 side.

 Under the present circumstances, since the base material layer 1 is a thing as the above-mentioned structure, the base material layer 1 exhibits the shape followability excellent with respect to the unevenness | corrugation 6 at the time of the heating of vacuum pressure forming.

 Therefore, in this state, the base layer 1 is deformed in accordance with the shape of the irregularities 6 by uniformly pressing from the electromagnetic wave shielding film 100 side while making the closed space under a vacuum atmosphere. Along with the deformation, the insulating layer 2 and the electromagnetic wave shielding layer 3 located closer to the substrate 5 than the base material layer 1 are deformed corresponding to the shape of the irregularities 6. Accordingly, the unevenness 6 is covered with the insulating layer 2 and the electromagnetic wave shielding layer 3 in a state where the insulating layer 2 and the electromagnetic wave shielding layer 3 are pushed in corresponding to the shape of the unevenness 6.

 In such a pasting step, the temperature for pasting is not particularly limited, but is preferably 100 ° C. or higher and 200 ° C. or lower, more preferably 120 ° C. or higher and 180 ° C. or lower.

 The pressure to be applied is not particularly limited, but is preferably 0.05 MPa or more and 5.0 MPa or less, more preferably 0.07 MPa or more and 3.0 MPa or less.

 Furthermore, the sticking time is not particularly limited, but is preferably 1 second or longer and 30 minutes or shorter, and more preferably 20 seconds or longer and 5 minutes or shorter.

By setting the conditions in the pasting step within the above range, the insulating layer 2 and the electromagnetic wave shielding layer 3 are pushed into the concave and convex portions 6 on the substrate 5, and the concave and convex portions 6 are formed by the insulating layer 2 and the electromagnetic wave shielding layer 3. It can be reliably coated.
(Peeling process)
The said peeling process is a process of peeling the base material layer 1 from the film 100 for electromagnetic wave shields after the said sticking process, for example, as shown in FIG.2 (b).

 By this peeling process, in this embodiment, peeling arises in the interface of the base material layer 1 and the insulating layer 2 in the electromagnetic wave shielding film 100, and as a result, the base material layer 1 is peeled from the insulating layer 2. Thus, the unevenness 6 is covered with the insulating layer 2 and the electromagnetic wave shielding layer 3 in a state where the base material layer 1 is peeled from the insulating layer 2.

 In addition, in the covering of the unevenness 6 with the insulating layer 2 and the electromagnetic wave shielding layer 3 using such an electromagnetic wave shielding film 100, as shown in FIG. 2, the shape of the electromagnetic wave shielding film 100 to be applied corresponds, The unevenness 6 can be covered with the insulating layer 2 and the electromagnetic wave shielding layer 3. Therefore, the unevenness 6 to be covered can be selectively covered with the insulating layer 2 and the electromagnetic wave shielding layer 3 by appropriately setting the shape of the electromagnetic wave shielding film 100 corresponding to the shape of the unevenness 6 to be covered. . That is, the electromagnetic wave can be selectively shielded from the unevenness 6 by the insulating layer 2 and the electromagnetic wave shielding layer 3.

 Further, the method for peeling the base material layer 1 is not particularly limited. However, when the electromagnetic wave shielding film 100 after the vacuum pressure forming (the pasting step) is in a high temperature state, the base material layer 1 is stretched and resin Since the remainder etc. generate | occur | produce and peeling workability | operativity may fall, the peeling by manual work is mentioned.

 In this manual peeling, for example, first, one end portion of the base material layer 1 is gripped, the base material layer 1 is peeled off from the insulating layer 2 from the gripped end portion, and then the central portion is cut from the end portion. Furthermore, the base material layer 1 is peeled from the insulating layer 2 by sequentially peeling the base material layer 1 to the other end.

 The peeling temperature is preferably 180 ° C. or lower, more preferably 150 ° C. or lower, and further preferably 100 ° C. or lower.

 By passing through the above processes, the unevenness | corrugation 6 can be coat | covered with the insulating layer 2 and the electromagnetic wave shielding layer 3 in the state which peeled the base material layer 1 from the insulating layer 2. FIG.

 In the present embodiment, as shown in FIG. 1, as the electromagnetic wave shielding film 100, the base material layer 1 (first layer 11, second layer 13, third layer 12) from the upper surface side. The case where the insulating layer 2 and the electromagnetic wave shielding layer 3 are laminated in this order to cover the unevenness 6 on the substrate 5 with the insulating layer 2 and the electromagnetic wave shielding layer 3 has been described. The layer configuration of 100 is not limited to this case, and may be, for example, the electromagnetic wave shielding film 100 having the layer configuration as shown in the second to fifth embodiments as described below.

Second Embodiment
Hereinafter, 2nd Embodiment of the film for electromagnetic wave shielding of this invention is described.

 FIG. 3 is a longitudinal sectional view showing a second embodiment of the electromagnetic wave shielding film of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 3 is referred to as “upper” and the lower side is referred to as “lower”.

 Hereinafter, although the electromagnetic wave shielding film 100 shown in FIG. 3 will be described, the description will focus on differences from the electromagnetic wave shielding film 100 shown in FIG. 1, and description of similar matters will be omitted.

 The electromagnetic wave shielding film 100 shown in FIG. 3 is the same as the electromagnetic wave shielding film 100 shown in FIG. 1 except that the formation of the first layer 11 included in the base material layer 1 is omitted.

 That is, in the present embodiment, the electromagnetic wave shielding film 100 includes the base material layer 1 including the second layer 13 and the third layer 12, the insulating layer 2, and the electromagnetic wave shielding layer 3 laminated in this order. The laminated body is made.

 In the electromagnetic wave shielding film 100 having such a configuration, the pressing portion of the vacuum pressurizing laminator or the like used when the insulating layer 2 and the electromagnetic wave shielding layer 3 are pressed into the unevenness 6 on the substrate 5 in the attaching step is the second layer. 13, so that the formation of the first layer 11 is omitted.

 In this case, the degree of releasability of the contact surface in contact with the second layer 13 of the pressing portion can be expressed by the surface tension of the contact surface, and the surface tension of the contact surface is 20 to 40 mN / m. It is preferable that it is 25-35 mN / m. When the contact surface has a surface tension within such a range, the pressing portion can be reliably peeled off from the second layer 13 after pressing using a vacuum pressurizing laminator or the like.

 The electromagnetic wave shielding film 100 of this embodiment having such a configuration can also be used in the same manner as the electromagnetic wave shielding film 100 of the first embodiment, and is similar to the electromagnetic wave shielding film 100 of the first embodiment. The effect is obtained.

<Third Embodiment>
Next, a third embodiment of the electromagnetic wave shielding film of the present invention will be described.

 FIG. 4 is a longitudinal sectional view showing a third embodiment of the electromagnetic wave shielding film of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 4 is referred to as “upper” and the lower side is referred to as “lower”.

Hereinafter, the electromagnetic wave shielding film 100 shown in FIG. 4 will be described, but the description will focus on the differences from the electromagnetic wave shielding film 100 shown in FIG. 1, and the description of the same matters will be omitted.

 The electromagnetic wave shielding film 100 shown in FIG. 4 is the same as the electromagnetic wave shielding film 100 shown in FIG. 1 except that the formation of the third layer 12 included in the base material layer 1 is omitted.

 That is, in this embodiment, the electromagnetic wave shielding film 100 includes the base material layer 1 including the first layer 11 and the second layer 13, the insulating layer 2, and the electromagnetic wave shielding layer 3 laminated in this order. The laminated body is made.

  In the electromagnetic wave shielding film 100 having such a configuration, when the base material layer 1 is peeled from the insulating layer 2 in the peeling step, the base material layer 1 is separated from the insulating layer 2 at the interface between the second layer 13 and the insulating layer 2. It is peeled off. In such peeling, the insulating layer 2 has releasability from the second layer 13, whereby the formation of the third layer 12 is omitted.

 In this case, the degree of releasability of the contact surface in contact with the second layer 13 of the insulating layer 2 can be expressed by the surface tension of the contact surface, and the surface tension of the contact surface is 20 to 40 mN / m. It is preferable that it is 25-35 mN / m. When the contact surface has a surface tension within such a range, the second layer 13 can be reliably peeled off from the insulating layer 2 after being pressed using a vacuum pressure laminator or the like.

 Examples of the insulating layer 2 having surface tension include thermoplastic polyester and α-olefin.

 The electromagnetic wave shielding film 100 of this embodiment having such a configuration can also be used in the same manner as the electromagnetic wave shielding film 100 of the first embodiment, and is similar to the electromagnetic wave shielding film 100 of the first embodiment. The effect is obtained.

<Fourth embodiment>
Next, a fourth embodiment of the electromagnetic wave shielding film of the present invention will be described.

  FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the electromagnetic wave shielding film of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 5 is referred to as “upper” and the lower side is referred to as “lower”.

 Hereinafter, although the electromagnetic wave shielding film 100 shown in FIG. 5 will be described, differences from the electromagnetic wave shielding film 100 shown in FIG. 1 will be mainly described, and description of similar matters will be omitted.

 The electromagnetic wave shielding film 100 shown in FIG. 5 is the same as the electromagnetic wave shielding film 100 shown in FIG. 1 except that the formation of the first layer 11 and the third layer 12 included in the base material layer 1 is omitted. It is the same.

 That is, in the present embodiment, the electromagnetic wave shielding film 100 forms a laminate in which the base material layer 1 composed of the second layer 13, the insulating layer 2, and the electromagnetic wave shielding layer 3 are laminated in this order. Yes.

  In the electromagnetic wave shielding film 100 having such a configuration, the pressing portion of the vacuum pressurizing laminator or the like used when the insulating layer 2 and the electromagnetic wave shielding layer 3 are pressed into the unevenness 6 on the substrate 5 in the attaching step is the second layer. 13, so that the formation of the first layer 11 is omitted. In the peeling process, when the base material layer 1 is peeled from the insulating layer 2, the base material layer 1 is peeled from the insulating layer 2 at the interface between the second layer 13 and the insulating layer 2. In such peeling, the insulating layer 2 has releasability from the second layer 13, whereby the formation of the third layer 12 is omitted.

 In the electromagnetic wave shielding film 100 having such a configuration, the resin constituting the second layer 13 of the base material layer 1 is an α-olefin polymer such as polyethylene or polypropylene, ethylene, propylene, butene, pentene, hexene, methylpentene, or the like. Engineering plastics resins such as α-olefin copolymers, polyesters, polyethersulfones, and polyphenylene sulfides.

 The electromagnetic wave shielding film 100 of this embodiment having such a configuration can also be used in the same manner as the electromagnetic wave shielding film 100 of the first embodiment, and is similar to the electromagnetic wave shielding film 100 of the first embodiment. The effect is obtained.

<Fifth Embodiment>
Next, a fifth embodiment of the electromagnetic wave shielding film of the present invention will be described.

  FIG. 6 is a longitudinal sectional view showing a fifth embodiment of the electromagnetic wave shielding film of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 5 is referred to as “upper” and the lower side is referred to as “lower”.

 Hereinafter, although the electromagnetic wave shielding film 100 shown in FIG. 6 will be described, the description will focus on differences from the electromagnetic wave shielding film 100 shown in FIG. 1, and description of similar matters will be omitted.

 In the electromagnetic wave shielding film 100 shown in FIG. 6, the formation of the third layer 12 included in the base material layer 1 is omitted, and the stacking order of the insulating layer 2 and the electromagnetic wave shielding layer 3 is reversed. This is the same as the electromagnetic wave shielding film 100 shown in FIG.

 That is, in this embodiment, the electromagnetic wave shielding film 100 includes the base material layer 1 including the first layer 11 and the second layer 13, the electromagnetic wave shielding layer 3, and the insulating layer 2 laminated in this order. The laminated body is made.

 In the electromagnetic wave shielding film 100 having such a configuration, when the base material layer 1 is peeled from the electromagnetic wave shielding layer 3 in the peeling step, the base material layer 1 is shielded from electromagnetic waves at the interface between the second layer 13 and the electromagnetic wave shielding layer 3. Peel from layer 3. In such peeling, the electromagnetic wave shielding layer 3 has releasability from the second layer 13, and thus the formation of the third layer 12 is omitted.

 In this case, the degree of releasability of the contact surface in contact with the second layer 13 of the electromagnetic wave shielding layer 3 can be expressed by the surface tension of the contact surface, and the surface tension of the contact surface is 20 to 40 mN / m is preferable, and 25 to 35 mN / m is more preferable. When the contact surface has a surface tension within such a range, the second layer 13 can be reliably peeled from the electromagnetic wave shielding layer 3 after being pressed using a vacuum pressurizing laminator or the like.

 As such an electromagnetic wave shielding layer 3 having surface tension, for example, a carbon allotrope or a conductive polymer dispersed in a thermosetting resin such as polyurethane can be used.

 The electromagnetic wave shielding film 100 of this embodiment having such a configuration can also be used in the same manner as the electromagnetic wave shielding film 100 of the first embodiment, and is similar to the electromagnetic wave shielding film 100 of the first embodiment. The effect is obtained.

<Sixth Embodiment>
Next, a sixth embodiment of the electromagnetic wave shielding film of the present invention will be described.

 FIG. 7 is a longitudinal sectional view showing a sixth embodiment of the electromagnetic wave shielding film of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 7 is referred to as “upper” and the lower side is referred to as “lower”.

 Hereinafter, although the electromagnetic wave shielding film 100 shown in FIG. 7 will be described, differences from the electromagnetic wave shielding film 100 shown in FIG. 1 will be mainly described, and description of similar matters will be omitted.

The electromagnetic wave shielding film 100 shown in FIG. 7 is the same as the electromagnetic wave shielding film 100 shown in FIG. 1 except that the stacking order of the insulating layer 2 and the electromagnetic wave shielding layer 3 is reversed.

  That is, in this embodiment, the electromagnetic wave shielding film 100 includes the base material layer 1 including the first layer 11, the second layer 13, and the third layer 12, the electromagnetic wave shielding layer 3, and the insulating layer 2. The laminated body is laminated in this order. By covering the unevenness 6 on the substrate 5 using the electromagnetic wave shielding film 100 including the electromagnetic wave shielding layer 3 and the insulating layer 2 laminated in this manner, the insulating layer 2 comes into contact with the substrate 5 and the electronic component 4, The insulating layer 2 and the electromagnetic wave shielding layer 3 are coated in this order from the substrate 5 side.

  As described above, in the present embodiment, the insulating layer 2 covers the substrate 5 and the electronic component 4 in contact with them, whereby the substrate 5 and the electronic component 4 are covered via the insulating layer 2. It insulates from the electromagnetic wave shielding layer 3 and other members (electronic parts etc.) located on the opposite side.

  Therefore, in the electromagnetic wave shielding film 100 having such a configuration, for example, even when the electromagnetic wave shielding layer 3 includes a conductive material, the adjacent electronic components 4 can be reliably insulated by the insulating layer 2. it can.

  The electromagnetic wave shielding film 100 of this embodiment having such a configuration can also be used in the same manner as the electromagnetic wave shielding film 100 of the first embodiment, and is similar to the electromagnetic wave shielding film 100 of the first embodiment. The effect is obtained.

  Moreover, in the said embodiment, although the insulating layer 2 demonstrated the case where one layer was laminated | stacked on either the upper surface or the lower surface of the electromagnetic wave shielding layer 3, it is not limited to such a case, For example, an electromagnetic wave shielding layer One layer may be laminated as a separate layer on each of the upper surface and the lower surface of 3, or the formation thereof may be omitted.

  Furthermore, in the above-described embodiment, unevenness is formed on the substrate by mounting the electronic component on the substrate, and the case where the unevenness is covered with the electromagnetic shielding film has been described. The coating is not limited to such unevenness, and for example, it may be applied to a flat region provided in a housing or the like.

<Seventh embodiment>
Next, a seventh embodiment of the electromagnetic wave shielding film of the present invention will be described.

  FIG. 8 is a longitudinal sectional view showing a seventh embodiment of the electromagnetic wave shielding film of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 8 is referred to as “upper” and the lower side is referred to as “lower”.

 Hereinafter, although the electromagnetic wave shielding film 100 shown in FIG. 8 will be described, the description will focus on the differences from the electromagnetic wave shielding film 100 shown in FIG. 6, and description of similar matters will be omitted.

 In the electromagnetic wave shielding film 100 shown in FIG. 8, except that the formation of the first layer 11 and the third layer 12 included in the base material layer 1 is omitted, the electromagnetic wave shielding film 100 shown in FIG. It is the same.

 That is, in the present embodiment, the electromagnetic wave shielding film 100 forms a laminated body in which the base material layer 1 composed of the second layer 13, the electromagnetic wave shielding layer 3, and the insulating layer 2 are laminated in this order. Yes.

  In the electromagnetic wave shielding film 100 having such a configuration, the pressing portion of the vacuum pressure laminator or the like used when the electromagnetic wave blocking layer 3 and the insulating layer 2 are pressed into the unevenness 6 on the substrate 5 in the attaching step is the second layer. 13, so that the formation of the first layer 11 is omitted. In the peeling step, when peeling the base material layer 1 from the electromagnetic wave shielding layer 3, the base material layer 1 is peeled from the electromagnetic wave shielding layer 3 at the interface between the second layer 13 and the electromagnetic wave shielding layer 3. In such peeling, the insulating layer 2 has releasability from the second layer 13, whereby the formation of the third layer 12 is omitted.

In the electromagnetic wave shielding film 100 having such a configuration, the resin constituting the second layer 13 of the base material layer 1 is an α-olefin polymer such as polyethylene or polypropylene, ethylene, propylene, butene, pentene, hexene, methylpentene, or the like. Engineering plastics resins such as α-olefin copolymers, polyesters, polyethersulfones, and polyphenylene sulfides.
The electromagnetic wave shielding film 100 of this embodiment having such a configuration can also be used in the same manner as the electromagnetic wave shielding film 100 of the first embodiment, and is similar to the electromagnetic wave shielding film 100 of the first embodiment. The effect is obtained.

  In the first embodiment to the seventh embodiment, after the pasting step, there is a step of peeling the base material layer 1 from the electromagnetic wave shielding film 100. The protective layer may be used without peeling off.

The electromagnetic shielding film and the electronic component mounting substrate of the present invention have been described above, but the present invention is not limited to these.

For example, in the electromagnetic wave shielding film of the present invention, the arbitrary configurations of the first to seventh embodiments can be combined.

Moreover, the arbitrary layers which can exhibit the same function may be added to the film for electromagnetic wave shields of this invention, and the electronic component mounting substrate of this invention.

 EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to this.

Example 1
<Preparation of pellet>
30 parts by mass of PAN-based carbon fiber (manufactured by Toho Tenax Co., Ltd., trade name: Tenax carbon fiber milled fiber HT M800 160MU, fiber diameter 7 μm, length 160 μm) and 70 parts by mass of SIS resin (styrene isoprene block copolymer, Japan Zeon Co., Ltd., trade name: QUINTAC 3280) was put into a twin screw extruder with a cylinder diameter of 45 mm and kneaded to prepare pellets.

<Manufacture of electromagnetic wave shielding layer film>
The pellet was placed on an electric heating press and molded into a film under conditions of a temperature of 220 ° C. and a pressure of 20 Mpa to obtain an electromagnetic wave shielding layer film.

 At this time, the electromagnetic wave shielding layer was 100 μm.

<Electromagnetic wave shielding>
About the electromagnetic wave shielding property evaluation film produced in Example 1, the electromagnetic wave shielding property which blocks | interrupts the electromagnetic wave in frequency 1GHz was measured using the microstrip line method mentioned above. Furthermore, the electromagnetic shielding property which interrupts | blocks the electromagnetic wave in frequency 1GHz was measured using KEC method mentioned above.

<Manufacture of electromagnetic shielding film>
In order to obtain an electromagnetic wave shielding film, syndiotactic polystyrene (manufactured by Idemitsu Kosan Co., Ltd., trade name: Zalec S107) was prepared as a resin constituting the first layer (first release layer). Syndiotactic polystyrene (manufactured by Idemitsu Kosan Co., Ltd., trade name: Zarek S107) was prepared as a resin constituting the third layer (second release layer). As the resin constituting the second layer (cushion layer), an ethylene-methyl acrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name: ACRIFT WD106) was prepared. A polyolefin emulsion (manufactured by Unitika Ltd., trade name: Arrow Base TC-4010) was prepared as a resin constituting the insulating layer. As the resin constituting the electromagnetic wave shielding layer, the electromagnetic wave shielding layer film prepared as described above was prepared.

The syndiotactic polystyrene as the first layer, the syndiotactic polystyrene as the third layer, and the ethylene-methyl acrylate copolymer as the second layer are combined using a feed block and a multi-manifold die. A film was formed by extrusion. The conductive electromagnetic wave shielding layer film was laminated on a base material layer as an electromagnetic wave shielding layer, and the electromagnetic wave shielding film was coated with the polyolefin emulsion as an insulating layer to produce an electromagnetic wave shielding film.
The total thickness of the electromagnetic wave shielding film of Example 1 is 240 μm, the thickness of the first layer is 30 μm, the thickness of the third layer is 30 μm, the thickness of the second layer is 60 μm, and the thickness of the insulating layer is The thickness of 20 μm and the electromagnetic wave shielding layer was 100 μm.

(Example 2)
50 parts by weight of PAN-based carbon fiber (manufactured by Toho Tenax Co., Ltd., trade name: Tenax carbon fiber milled fiber HT M800 160MU) and 50 parts by weight of SIS resin (manufactured by Nippon Zeon Co., Ltd., trade name: QUINTAC) Except that 3280) was used, pellets were prepared in the same manner as in Example 1 to prepare an electromagnetic wave shielding layer film and an electromagnetic wave shielding film.

(Example 3)
50 parts by weight of pitch-based carbon fiber (manufactured by Cytec, trade name: THORNEL DKD fiber diameter 10 μm, length 200 μm) and 50 parts by weight of SIS resin (manufactured by Nippon Zeon Co., Ltd., trade name: QUINTAC 3280) Except having used, it carried out similarly to Example 1, and produced the pellet, and produced the electromagnetic wave shielding layer film and the film for electromagnetic wave shielding.

Example 4
Example except that 70 parts by weight of pitch-based carbon fiber (made by Cytec, trade name: THORNEL DKD) and 30 parts by weight of SIS resin (made by Nippon Zeon Co., Ltd., trade name: QUINTAC 3280) were used. In the same manner as in Example 1, pellets were prepared, and an electromagnetic wave shielding layer film and an electromagnetic wave shielding film were produced.

(Example 5)
70 parts by weight of pitch-based carbon fiber (manufactured by Kureha Co., Ltd., trade name: KCF-100 M1009S, fiber diameter: 14.5 μm, length: 100 μm) and 30 parts by weight of SIS resin (manufactured by Nippon Zeon Co., Ltd., product) A pellet was prepared in the same manner as in Example 1 except that name: QUINTAC 3280) was used, and an electromagnetic wave shielding layer film and an electromagnetic wave shielding film were produced.

(Example 6)
70 parts by weight of pitch-based carbon fiber (manufactured by Osaka Gas Chemical Co., Ltd., trade name: S-242, fiber diameter 13 μm, length 370 μm) and 30 parts by weight of SIS resin (manufactured by Nippon Zeon Co., Ltd., trade name) : Quintac 3280) was used in the same manner as in Example 1 except that pellets were produced, and an electromagnetic wave shielding layer film and an electromagnetic wave shielding film were produced.

(Example 7)
70 parts by weight of pitch-based carbon fiber (made by Cytec, trade name: THORNEL DKD) and 30 parts by weight of SEBS resin (hydrogenated styrene-based thermoplastic elastomer, made by Aron Kasei Co., Ltd., trade name: AR-FL-75N Except that was used, pellets were prepared in the same manner as in Example 1 to prepare an electromagnetic wave shielding layer film and an electromagnetic wave shielding film.

(Example 8)
Example 1 except that 70 parts by weight of pitch-based carbon fiber (Cytech, trade name: THORNEL DKD) and 30 parts by weight of polypropylene resin (Sumitomo Chemical Co., trade name: Nobrene FS2011DG2) were used. In the same manner as above, pellets were prepared, and an electromagnetic wave shielding layer film and an electromagnetic wave shielding film were produced.

(Comparative Example 1)
Except for using 20 parts by weight of pitch-based carbon fiber (product name: THORNEL DKD) manufactured by Cytec Co., Ltd. and 80 parts by weight of SIS resin (product name: QUINTAC 3280 manufactured by Nippon Zeon Co., Ltd.) In the same manner as in Example 1, pellets were prepared, and an electromagnetic wave shielding layer film and an electromagnetic wave shielding film were produced.

(Comparative Example 2)
Except for using 20 parts by weight of pitch-based carbon fiber (manufactured by Kureha Co., Ltd., trade name: KCF-100) and 80 parts by weight of SIS resin (manufactured by Nippon Zeon Co., Ltd., trade name: QUINTAC 3280) In the same manner as in Example 1, pellets were produced, and an electromagnetic wave shielding layer film and an electromagnetic wave shielding film were produced.

(Comparative Example 3)
20 parts by weight of pitch-based carbon fiber (manufactured by Osaka Gas Chemical Co., Ltd., trade name: S-242) and 80 parts by weight of SIS resin (manufactured by Nippon Zeon Co., Ltd., trade name: QUINTAC 3280) are used. Except for the above, pellets were produced in the same manner as in Example 1, and an electromagnetic wave shielding layer film and an electromagnetic wave shielding film were produced.

 The results are shown in Table 1.

As is apparent from Table 1, in Examples 1 to 8, even if the electromagnetic wave was in a high frequency band such as 1 GHz, the result of being effectively blocked by absorbing the electromagnetic wave was obtained.

 On the other hand, in the comparative example, compared with Examples 1-8, it was a result that it cannot be said that the electromagnetic wave of a high frequency band was interrupted | blocked effectively.

DESCRIPTION OF SYMBOLS 100 Electromagnetic wave shielding film 1 Base material layer 11 1st layer 12 3rd layer 13 2nd layer 2 Insulating layer 3 Electromagnetic wave blocking layer 4 Electronic component 5 Substrate 6 Concavity and convexity 61 Convex part

Claims (12)

A film having an electromagnetic wave shielding layer,
The electromagnetic wave shielding layer contains carbon fiber and a thermoplastic resin, and the carbon fiber contains 30% by mass or more in the electromagnetic wave shielding layer.  2. The electromagnetic wave shielding film according to claim 1, wherein the thermoplastic resin is a thermoplastic elastomer.  The electromagnetic shielding film according to claim 1, wherein the thermoplastic elastomer is a styrene elastomer.  The electromagnetic wave shielding film according to any one of claims 1 to 3, wherein the carbon fiber has an aspect ratio of 5 or more and 200 or less.  5. The electromagnetic wave shielding according to claim 1, wherein the electromagnetic wave shielding layer has an electromagnetic wave shielding effect of 5 dB or more when measured using a microstrip line method in an electromagnetic wave having a frequency of 0.2 to 1 GHz. Film.  The electromagnetic wave shielding film according to any one of claims 1 to 5, wherein the electromagnetic wave shielding layer has an electromagnetic wave shielding effect of 7 dB or more when measured using a KEC method in an electromagnetic wave having a frequency of 0.2 to 1 GHz. .  The film for electromagnetic wave shielding according to claim 1, wherein the electromagnetic wave shielding layer has a thickness of 1 μm or more and 150 μm or less.  The film for electromagnetic wave shielding of any one of Claims 1 thru | or 7 provided with the base material layer laminated | stacked on the single side | surface of the said electromagnetic wave shielding layer.  The film for electromagnetic wave shielding of any one of Claim 1 thru | or 7 provided with the insulating layer laminated | stacked on the single side | surface of the said electromagnetic wave shielding layer.  The electromagnetic wave according to any one of claims 1 to 7, further comprising a base material layer laminated on one side of the electromagnetic wave shielding layer, and further comprising an insulating layer laminated on a surface opposite to the base material layer. Shield film.  The electromagnetic wave shielding film according to any one of claims 1 to 10, wherein the electromagnetic wave shielding film is used for covering irregularities on a substrate. An electronic component mounting substrate comprising: a substrate; an electronic component mounted on the substrate; and an electromagnetic wave shielding layer that covers the substrate and the electronic component from a side of the substrate on which the electronic component is mounted. ,
The electronic component mounting substrate, wherein the electromagnetic wave shielding layer contains carbon fiber and a thermoplastic resin.