JP2016181615A - Shield material, substrate with shield material and manufacturing method of substrate with shield material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield material capable of satisfying both of the flexibility of the substrate and the insulation property between the surface of the substrate and the shield material, and to provide a substrate with shield material and a manufacturing method of the substrate with shield material.SOLUTION: A shield material 1 includes: a plastic film 2; an adhesion layer 3 which is formed over one side of the plastic film 2; and a metal foil 4 which is bonded to the first adhesion layer 3. The metal foil 4 is constituted by an electrolytic metal foil or a rolled metal foil, the thickness of which is 0.3-9.9 μm. The surface roughness (Rz) of the metal foil 4 at the side facing the first adhesion layer 3 is 0.01-1.50 μm.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shield material, a substrate with a shield material, and a method for manufacturing a substrate with a shield material.

  In recent years, with the remarkable development of electronic application devices, thin and flexible tape-like substrates are widely used. Here, the substrate includes both a flat cable and a flexible substrate.

  Especially for AV equipment such as VTR, CD or DVD player, OA / PC peripheral equipment such as copiers, scanners and printers, and other electronic / electrical equipment, the board is required to have electromagnetic shielding characteristics from the viewpoint of noise prevention. Often done.

  Conventionally, as a method of imparting electromagnetic wave shielding characteristics to a substrate, a method of attaching a composite tape in which a polyester film is bonded to the surface of a copper foil (Patent Document 1), or an insulating plastic such as polyethylene terephthalate (PET) There is known a method (Patent Documents 2 and 3) in which a shielding material having an outermost layer, a conductive metal such as Cu or Al as an intermediate layer, and a conductive adhesive as an innermost layer is bonded to both surfaces of a flat cable.

Japanese Patent Laid-Open No. 02-168512 JP 2004-031141 A JP 2007-299704 A

  However, when a composite tape in which a polyester film is bonded to the surface of a copper foil is attached to a flat cable, the thickness of the entire flat cable is increased and the flexibility of the flat cable may be hindered.

  In addition, the method of laminating a shielding material with insulating plastic as the outermost layer, conductive metal as the intermediate layer, and conductive adhesive as the innermost layer is performed between the surface of the board and the shielding material. It may not be suitable if it is necessary to ensure

  The present invention has been made in view of the above points, and a shield material, a substrate with a shield material, and a shield material capable of ensuring both the flexibility of the substrate and the insulation between the surface of the substrate and the shield material, and It aims at providing the manufacturing method of a board | substrate with a shielding material.

  The shield material according to the present invention includes a plastic film, a first adhesive layer formed on one side of the plastic film, and a metal foil adhered on the first adhesive layer. The metal foil is made of an electrolytic metal foil or a rolled metal foil having a thickness of 0.3 μm or more and 9.9 μm or less. The surface roughness (Rz) of the side facing the first adhesive layer of the metal foil is 0.01 μm or more and 1.50 μm or less.

  In the shield material, it is preferable that the first adhesive layer includes at least one resin selected from an acrylic resin, an epoxy resin, and a urethane resin.

  In the shield material, the glass transition temperature of the first adhesive layer is preferably lower than the glass transition temperature of the plastic film.

  In the shield material, the thickness of the first adhesive layer is preferably 0.1 μm or more and 10.0 μm or less.

  In the shield material, the elastic modulus at 25 ° C. of the first adhesive layer is preferably 1000.0 GPa or less.

  The substrate with a shield material according to the present invention includes a substrate, a second adhesive layer formed on the surface of the substrate, and the shield material that is adhered onto the second adhesive layer and covers the substrate. The shield material is arranged so that the plastic film is on the substrate side.

  The method for manufacturing a substrate with a shield material according to the present invention includes a step of preparing a shield material in which a metal foil is bonded to one side of a plastic film via a first adhesive layer, the plastic film of the shield material, and a substrate. Is attached with an adhesive for forming a second adhesive layer to form a second adhesive layer. The metal foil is made of an electrolytic metal foil or a rolled metal foil having a thickness of 0.3 μm or more and 9.9 μm or less, and the surface roughness (Rz) of the side facing the first adhesive layer of the metal foil is 0.00. It is 01 μm or more and 1.50 μm or less. The shield material is arranged so that the plastic film is on the substrate side.

  According to the present invention, the metal foil is made of an electrolytic metal foil or a rolled metal foil having a thickness of 0.3 μm or more and 9.9 μm or less, and the surface roughness (Rz) of the surface of the metal foil facing the first adhesive layer is Since it is 0.01 μm or more and 1.50 μm or less, a shield material (thickness is 50 μm or more) using a commercially available copper foil (surface roughness (Rz) is 2.0 μm or more, and further 7.0 μm or more) ), The overall thickness of the shield material can be reduced. Therefore, the substrate can be covered with a shield material thinner than the conventional one, the thickness of the substrate can be prevented, and the flexibility of the substrate can be ensured. Furthermore, if the substrate and the shield material are bonded together so that the plastic film of the shield material is on the substrate side, the metal foil is bonded to the substrate through the plastic film, so the space between the surface of the substrate and the shield material Insulation can be ensured.

It is sectional drawing for demonstrating the layer structure of the shielding material which concerns on one Embodiment of this invention. It is a partial cross section figure for demonstrating the structure of the board | substrate with a shielding material which concerns on one Embodiment of this invention. It is sectional drawing which shows the use condition of the board | substrate with a shielding material which concerns on one Embodiment of this invention. 4A and 4B are cross-sectional views for explaining an apparatus for producing a metal foil.

  Hereinafter, the present invention will be specifically described with reference to embodiments.

[Shield material 1]
FIG. 1 is a cross-sectional view for explaining a layer structure of a shield material 1 according to an embodiment of the present invention.

  As shown in FIG. 1, the shield material 1 includes a plastic film 2, a first adhesive layer 3 formed on one surface of the plastic film 2, and a metal foil 4 bonded on the first adhesive layer 3. The metal foil 4 is made of an electrolytic metal foil or a rolled metal foil having a thickness of 0.3 μm or more and 9.9 μm or less, and the surface roughness (Rz) on the side of the metal foil 4 facing the first adhesive layer 3, that is, The surface roughness (Rz) of the surface of the metal foil to which the first adhesive layer 3 is bonded is 0.01 μm or more and 1.50 μm or less. Thereby, the thickness of the entire shield material 1 from a shield material (thickness of 50 μm or more) having the same configuration using a commercially available copper foil (surface roughness (Rz) of 2.0 μm or more, and further 7.0 μm or more). Can be made thinner. Therefore, the board | substrate 20 can be covered with the shielding material 1 thinner than before, the thickness increase of the board | substrate 20 can be prevented, and the flexibility of the board | substrate 20 can be ensured. Furthermore, if the board | substrate 20 and the shielding material 1 are bonded together so that the plastic film 2 of the shielding material 1 may become the board | substrate 20 side, ie, the plastic film 2 of the shielding material 1 may face the board | substrate 20, metal foil 4 will become Since it adheres to the substrate 20 via the plastic film 2, the insulation between the surface of the substrate 20 and the shield material 1 can be ensured.

Here, the surface roughness (Rz) is a ten-point average roughness (R _ZJIS ) defined in JIS B 0601-2013, and only the reference length is _{measured in} the direction of the average line from the roughness curve. The average value of the absolute values of the highest peak (Yp) from the highest peak to the fifth and the lowest from the lowest to the fifth, measured in the direction of the vertical magnification from the average line of the extracted part. The sum of the absolute value of (Yv) and the average value is obtained, and this value is expressed in micrometers (μm).

  The thickness of the shielding material 1 is preferably 10 μm or more and 50 μm or less, more preferably 20 μm or more and 40 μm or less.

(Plastic film 2)
The material constituting the plastic film 2 is not particularly limited as long as it is an insulating and flexible material. For example, PET, polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), or the like can be used.

  The thickness of the plastic film 2 is preferably 10 μm or more and 45 μm or less, more preferably 20 μm or less and 30 μm or more.

(First adhesive layer 3)
The material constituting the first adhesive layer 3 is not particularly limited as long as it has excellent adhesion between the plastic film 2 and the metal foil 4 and has insulation, moisture resistance, aging resistance, and mechanical properties. For example, it is preferable to include at least one resin selected from an acrylic resin, an epoxy resin, and a urethane resin.

  The glass transition temperature (Tg) of the first adhesive layer 3 is preferably lower than the glass transition temperature (Tg) of the plastic film 2. Thereby, the elasticity modulus of the 1st contact bonding layer 3 can be made small, and the 1st contact bonding layer 3 comes to function more as a stress relaxation layer between the plastic film 2 and the metal foil 4. FIG. Therefore, in the obtained substrate 10 with a shielding material, disconnection of the circuit 22 due to the bending of the substrate 10 with a shielding material is less likely to occur. In order to make the glass transition temperature (Tg) of the first adhesive layer 3 lower than the glass transition temperature (Tg) of the plastic film 2, for example, the first adhesive layer 3 is configured according to the material constituting the plastic film 2. What is necessary is just to select a material suitably.

  The glass transition temperature (Tg) can be obtained as a temperature at which tan α exhibits a maximum by performing dynamic viscoelasticity measurement (DMA) using a viscoelastic spectrometer “DMS100” manufactured by Seiko Instruments Inc. .

  The elastic modulus at 25 ° C. of the first adhesive layer 3 is preferably 1000.0 GPa or less, more preferably 0.1 GPa or more and 100.0 GPa or less, and further preferably 0.6 GPa or more and 60.0 GPa or less. If the elastic modulus at 25 ° C. of the first adhesive layer 3 is within the above range, the first adhesive layer 3 easily functions as a stress relaxation layer between the plastic film 2 and the metal foil 4. Thereby, in the obtained board | substrate 10 with a shielding material, the disconnection of the circuit 22 by the bending of the board | substrate 10 with a shielding material becomes difficult to generate | occur | produce. In order to set the elastic modulus at 25 ° C. of the first adhesive layer 3 to 1000.0 GPa or less, for example, by adjusting the type and blending ratio of the resin contained in the adhesive such as acrylic resin, epoxy resin, and urethane resin Good.

  For the measurement of the elastic modulus, for example, a commercially available measuring device used for measuring the flexural modulus (JIS K7171) or the tensile elastic modulus (JIS K7162) can be used. When the thickness of the first adhesive layer 3 is 10 μm or less and it is difficult to directly measure the elastic modulus of the first adhesive layer 3, a Vickers hardness meter or a micro Vickers hardness meter can be used. Further, a quadrangular pyramid indenter (or measuring head) of a micro Vickers hardness tester is respectively applied to the first adhesive layer 3 to be measured under a microscope with a predetermined pressure (for example, a micro hardness tester “HM-211 made by Mitutoyo”. ”, The test force generation range is 0.4903 to 19610 mN), and the obtained measurement value is a rubber sheet for elastic modulus evaluation having a thickness of 1 mm or more prepared for comparison (for example, a commercially available silicon rubber sheet, etc. The elastic modulus of the rubber sheet for elastic modulus evaluation can be used as it is as the elastic modulus of the first adhesive layer 3.

  The thickness of the 1st contact bonding layer 3 becomes like this. Preferably they are 0.1 micrometer or more and 10.0 micrometers or less, More preferably, they are 0.5 micrometer or more and 5 micrometers or less, More preferably, they are 1 micrometer or more and 3 micrometers or less.

(Metal foil 4)
The material constituting the metal foil 4 is not particularly limited as long as it is a material capable of imparting electromagnetic wave shielding characteristics to the substrate. For example, copper, aluminum, nickel, stainless steel, mild steel, Fe—Ni alloy, white or the like Can be used.

  The metal foil 4 is made of an electrolytic metal foil or a rolled metal foil. Hereinafter, when the metal foil 4 is made of an electrolytic metal foil, it may be referred to as an electrolytic metal foil 4, and when the metal foil 4 is made of a rolled metal foil, it may be referred to as a rolled metal foil 4. Here, the electrolytic metal foil is a metal foil obtained by an electrolysis method. The rolled metal foil is a metal foil obtained by a rolling method. A roughened film may be formed on the surface of the metal foil 4 on the side facing the first adhesive layer 3. Examples of the roughening film include a plating film. For example, the plating film may contain at least one of Ni, sulfur, Co, W, Al and the like at a ratio of 0.01 to 10.0%. The roughened film is formed, for example, by a roughening process described later.

  The thickness of the metal foil 4 is 0.3 μm or more and 9.9 μm or less, preferably 0.5 μm or more and 5 μm or less, more preferably 1 μm or more and 3 μm or less. If the thickness of the metal foil is less than 0.3 μm, there is a possibility that sufficient electromagnetic wave shielding characteristics cannot be imparted to the substrate with shield material 10. On the other hand, when the thickness of the metal foil exceeds 9.9 μm, the flexibility of the substrate 10 with the shielding material may be lowered. Here, when a roughened film is formed on the surface of the metal foil 4 facing the first adhesive layer 3, the thickness of the metal foil 4 includes the thickness of the roughened film. The thickness of the roughened film is preferably 0.01 μm or more and 1.50 μm or less.

  The surface roughness (Rz) of the surface of the metal foil 4 facing the first adhesive layer 3 is 0.01 μm or more and 1.50 μm or less, preferably 0.05 μm or more and 1.00 μm or less, more preferably 0.10 μm. It is 0.50 μm or less. If the surface roughness (Rz) is less than 0.01 μm, the adhesion strength between the metal foil 4 and the first adhesive layer 3 may not be sufficient. On the other hand, if the surface roughness (Rz) exceeds 1.50 μm, the first adhesive layer prevents the plastic film 2 and a part of the metal foil 4 from contacting each other when the shielded substrate 10 is bent and used. Of the conventional copper foil (surface roughness (Rz) is not less than 2.0 μm, more preferably not less than 7.0 μm) is required to be adjusted to be equal to the conventional thickness (for example, 20 μm or more). There is a possibility that the thickness of the entire shield material 1 cannot be reduced as compared with the shield material having the same configuration. Here, the surface roughness (Rz) is a value measured in the same manner as in the examples.

  The surface roughness (Rz) of the surface of the metal foil 4 that does not face the first adhesive layer 3 is not particularly limited, and is preferably 0.1 μm or more and 7.0 μm or less.

  In addition, the value of the surface roughness (Rz) of the metal foil 4 is smaller than the value of the thickness of the metal foil 4.

[Substrate with shield material 10]
FIG. 2 is a partial cross-sectional view for explaining the configuration of the substrate with shield material 10 according to one embodiment of the present invention.

  The substrate with shield material 10 includes a substrate 20, a second adhesive layer 30 formed on the surface of the substrate 20, and a shield material 1 that is bonded onto the second adhesive layer 30 and covers the substrate 20. Are arranged so that the plastic film 2 is on the substrate 20 side. The shielded substrate 10 has a connecting portion (non-movable portion) 10A for electrically connecting to a main substrate or the like at one end thereof, and a flexible movable portion 10B. In the connection portion 10 </ b> A, the second adhesive layer 30 is formed on the entire surface of the substrate 20 opposite to the surface electrically connected to the substrate, and the shield material 1 covers the second adhesive layer 30. 2 Adhered on the adhesive layer 30. Further, in the movable portion 10 </ b> B, the second adhesive layer 30 is formed on the entire surface of both surfaces of the substrate 20, and the shield material 1 is bonded onto the second adhesive layer 30 so as to cover the second adhesive layer 30. Here, a movable part means the site | part which can be twisted and bent.

  Thus, since the board | substrate 20 is covered with the shielding material 1 whose both surfaces are thinner than before in the movable part 10B in the movable part 10B, the board | substrate 20 does not thicken the board | substrate 20, but electromagnetically shields it to the board | substrate 20. It is possible to impart characteristics and to ensure the flexibility of the substrate 20 at the same time. Furthermore, since the shielding material 1 is disposed so that the plastic film 2 is on the substrate 20 side, the metal foil 4 is bonded to the substrate 20 via the plastic film 2. Therefore, insulation between the metal foil 4 and the surface of the substrate 20 can be ensured.

  The external shape of the board | substrate 10 with a shielding material is not specifically limited, What is necessary is just to adjust suitably according to the use application etc. of the board | substrate 10 with a shielding material. 10 A of connection parts may be formed only in the one end part of the board | substrate 10 with a shielding material, and may be formed in the both ends of the board | substrate 10 with a shielding material, and it adjusts suitably according to the use application of the board | substrate 10 with a shielding material. do it. Moreover, a semiconductor device, a chip component, a connector, or the like may be mounted on the substrate 10 with the shield material as necessary.

  The substrate 20 includes a base film 21 and circuits 22 provided on both sides of the base film 21. The substrate 20 may be an adhesive type substrate in which the base film 21 and the circuit 22 are bonded together via a known epoxy or acrylic adhesive, or the substrate 20 is bonded between the base film 21 and the circuit 22. It may be a non-adhesive type substrate in which no agent is present. Especially, it is preferable that it is a non-adhesive type from a viewpoint of ensuring the flexibility of the board | substrate 20, etc. In addition, the board | substrate with which the circuit was formed in the single side | surface of a base film may be sufficient as the board | substrate in this invention.

  The material which comprises the base film 21 should just be a material which has heat resistance, insulation, flexibility, and flexibility, for example, a polyimide resin, a polyester resin, etc. can be used. The thickness of the base film 21 is preferably 10 μm or more and 300 μm or less, more preferably 30 μm or more and 100 μm or less. As a material constituting the circuit 22, for example, copper, aluminum, nickel, stainless steel, mild steel, Fe—Ni alloy, white or the like can be used. The thickness of the circuit 22 is preferably 1 μm or more and 35 μm or less, more preferably 3 μm or more and 18 μm or less.

  The second adhesive layer 30 is formed using an adhesive for forming a second adhesive layer (hereinafter sometimes referred to as a second adhesive).

  The material constituting the second adhesive is not particularly limited as long as it has excellent adhesion between the shield material 1 and the substrate 20, and has insulating properties, moisture resistance, aging resistance, and mechanical properties. A thermosetting resin such as an epoxy resin can be used as a main component. In particular, a thermosetting resin such as an epoxy resin having a glass transition temperature (Tg) of 200 ° C. or lower (lower limit is 80 ° C.) is preferable. Thereby, for example, as described later, when the second adhesive is formed in a semi-cured state on the shield material 1 or the substrate 20 when the substrate 10 with the shield material is manufactured, the temperature of the thermocompression bonding is 180 ° C. or less. Can be.

  The thickness of the second adhesive layer 30 is preferably 2 μm or more and 50 μm or less, more preferably 5 μm or more and 20 μm or less.

  The board | substrate 10 with a shielding material is useful for the various electronic devices represented by mobile electronic devices, such as a mobile telephone and a smart phone.

  FIG. 3 is a cross-sectional view showing a usage state of the substrate with shield material 10 according to the embodiment of the present invention. For example, as shown in FIG. 3, the shielded substrate 10 is electrically connected to a main substrate 300 in which insulating resin layers and inner layer circuits are alternately stacked, and the outer layer circuit 310 is provided on the outermost layer of the insulating resin layer. And used. A connection outer layer circuit 310A formed for electrical connection with the shielded substrate 10 in the outer layer circuit 310 and a connection circuit 22A formed for electrical connection with the main substrate 300 in the circuit 22 With the conductive adhesive layer 400 interposed therebetween, the shielded substrate 10 and the main substrate 300 are electrically connected.

  Through holes for electrically connecting the outer layer circuit 310 and the inner layer circuit, and the inner layer circuit and the inner layer circuit located on the front or back surface of the inner layer circuit via an insulating resin layer as necessary. A blind via hole or the like may be formed.

  As the insulating resin layer, for example, a substrate (FR-4 substrate) formed by impregnating glass fiber with an epoxy resin can be used. As a material constituting the inner layer circuit, for example, copper, aluminum, nickel, stainless steel, mild steel, Fe—Ni alloy, white or the like can be used.

  The conductive adhesive layer 400 is obtained by curing a thermosetting resin composition containing a solder resin and a thermosetting resin, for example. In electrically connecting the substrate with shield material 10 and the main substrate 300, first, a paste-like thermosetting resin composition in which solder particles are dispersed is placed on the conductive adhesive layer 400 using a syringe or the like. Apply. Next, the connection circuit 22A and the connection outer layer circuit 310A are aligned, and heating is performed with the thermosetting resin composition interposed between the connection circuit 22A and the connection outer layer circuit 310A. During the heating, the thermosetting resin is cured and the solder particles are melted at the same time. As a result, the connection region between the shielded substrate 10 and the main substrate 300 is bonded with the cured thermosetting resin composition, and at the same time, the connection circuit 22A and the connection outer layer circuit 310A are fused with the molten solder particles. The shielded substrate 10 and the main substrate 300 are electrically connected.

  In this state of use, the conductive adhesive layer 400 is interposed between the connection circuit 22A and the connection outer layer circuit 310A. For example, the connection circuit 22A and the connection outer layer circuit 310A are directly soldered. Alternatively, instead of the conductive adhesive layer 400, solder, copper, nickel, gold, bumps containing these composites, or the like may be used. When a bump is interposed between the connection circuit 22A and the connection outer layer circuit 310A, an underfill is formed in the gap between the overlapping portions of the shield-coated substrate 10 and the main substrate 300, and the shield-coated substrate 10 and the main substrate 300 are thus formed. And may be adhered. When the connection circuit 22A and the connection outer layer circuit 310A have the same pattern, a screw hole into which a fixing screw can be screwed is formed in the shielded substrate 10, and the connection circuit 22A is connected. Alignment with the outer layer circuit 310A, the main board 300, the board 10 with the shield material, and the fixture are arranged in this order, and the fixing screws are screwed in from above the fixture to attach the board 10 with the shield material to the main board. It may be clamped and fixed between 300 and the fixture.

[Manufacturing Method of Substrate with Shield Material 10]
The manufacturing method of the board | substrate 10 with a shielding material includes the process (a) which prepares the shielding material 1, and the process (b) which forms the 2nd contact bonding layer 30. FIG.

(Process (a) for preparing shield material 1)
In the step (a), for example, a step (a1) of manufacturing the metal foil 4 and a step (a2) of bonding the metal foil 4 to one surface of the plastic film 2 via the first adhesive layer 3 are included.

  In step (a1), the metal foil 4 is manufactured. As a manufacturing method of the metal foil 4, for example, an untreated electrolytic metal foil is deposited by an electrolytic method, and a surface of the deposited untreated electrolytic metal foil is roughened; a metal sheet is rolled and rolled Examples include a method of roughening the surface of the untreated rolled metal foil. Examples of the roughening method include, for example, a black oxidation method for roughening the surface by oxidizing, a chemical reduction method for roughening by reducing the surface treated by the black oxidation method, and the surface For example, an electroless copper plating method for roughening by electroless copper plating may be used.

  In order to set the thickness of the metal foil 4 to 0.3 μm or more and 9.9 μm or less, in the case of the electrolytic metal foil 4, for example, the voltage applied to the conductive support 240 may be adjusted as described later. In addition, when the surface roughness (Rz) of the surface of the metal foil 4 facing the first adhesive layer 3 is set to 0.01 μm or more and 1.50 μm or less, the roughening treatment is performed by an electrolytic roughening method. May adjust the roughening treatment time for immersing the untreated electrolytic metal foil or untreated rolled metal foil in the roughening solution, the concentration of the roughening solution, the liquid temperature of the roughening solution, and the like.

  In step (a2), the metal foil 4 is bonded to one side of the plastic film 2 via the first adhesive layer 3. Specifically, the first adhesive mainly composed of the material constituting the first adhesive layer 3 described above is applied to one side of the plastic film 2 or one side of the metal foil 4 to form a coating film (hereinafter referred to as the first coating film). The plastic film 2, the first coating film, and the metal foil 4 are laminated so as to be in this order, and are laminated and integrated by thermocompression bonding. At this time, the metal foil 4 is arranged so that the surface having the surface roughness (Rz) of the metal foil 4 of 0.01 μm or more and 1.50 μm or less becomes the first coating film side. A shield comprising the plastic film 2, the first adhesive layer 3 formed on one surface of the plastic film 2, and the metal foil 4 adhered on the first adhesive layer 3 as shown in FIG. 1 through the step (a2). Material 1 is obtained.

  As a method for thermocompression bonding, for example, a die press, a laminator, or the like can be used. The temperature during thermocompression bonding is preferably 100 to 150 ° C., the treatment time is preferably about 1 to 10 minutes, and the atmosphere is preferably 0.05 to 0.20 MPa.

  Hereinafter, an example of a method for producing the electrolytic metal foil 4 will be specifically described.

  4A and 4B are cross-sectional views for explaining an apparatus for manufacturing the metal foil 4.

  First, the power source 200 is connected to the insoluble anode 210 and the conductive support 240, and the insoluble anode 210 and the conductive support 240 are immersed in the electrolytic solution 220 in the treatment tank 230, so that untreated electrolysis is performed on the surface of the conductive support 240. Metal foil 150 is deposited.

  At this time, the metal foil 150 having a thickness of 0.3 μm or more and 9.9 μm or less can be obtained by optimizing a method of applying a voltage applied to the conductive support 240. In addition, by continuously depositing the untreated electrolytic metal foil 150 on the surface of the conductive support 240, the untreated electrolytic metal foil 150 with reduced thickness variation can be obtained.

  The electrolytic solution 220 may be appropriately selected according to the material constituting the metal foil 4 as long as it is a solution capable of electrolytically depositing the untreated electrolytic metal foil 150 having a purity equivalent to that of the metal foil 4. When the material constituting the metal foil 4 is copper, for example, a copper sulfate solution can be used. The treatment tank 230 is a batch-type water tank, but a drum-type water tank or a drum-type facility corresponding to a long length can be used. By using the equipment corresponding to the long length, the quality of the long metal foil 4 can be stabilized. The conductive support 240 is, for example, a metal plate such as a copper plate, a long copper foil, or a SUS plate. For example, a commercially available metal foil such as an electrolytic copper foil having a thickness of 18 μm can be used.

  It is preferable to form a conductive release layer (not shown) on the surface of the conductive support 240 and then deposit the untreated electrolytic metal foil 150 on the surface of the release layer. Thereby, workability | operativity which peels the metal foil 4 from the electrically conductive support body 240 can be improved. As a peeling layer, what is necessary is just to have electroconductivity, For example, the metal layer etc. which mainly have nickel with a thickness of 1 micrometer or less are mentioned.

  When the conductive support 240 is made of an electrolytic copper foil, the untreated electrolytic metal foil 150 is deposited on the glossy surface (or the surface having a small surface roughness) of the conductive support 240 made of the electrolytic copper foil. An untreated electrolytic metal foil 150 that is thin and has a small thickness variation can be deposited. Further, by utilizing the fact that the surface roughness of the conductive support 240 made of the electrolytic copper foil is transferred as the surface roughness of the untreated electrolytic metal foil 150 through the conductive release layer, the untreated electrolytic metal is used. The surface roughness of the foil 150 can be adjusted.

  Thereafter, as shown in FIG. 4B, the obtained untreated electrolytic metal foil 150 with the conductive support 240 is immersed in the roughening liquid 260 in the treatment tank 250, so that the conductive support of the untreated electrolytic metal foil 150 is obtained. A roughening process is performed on the surface on which 240 is not attached. Thereby, the metal foil 4 with the conductive support 240 is obtained.

  At this time, by optimizing the roughening treatment time for immersing the untreated electrolytic metal foil 150 in the roughening liquid 260, the concentration of the roughening liquid 260, the liquid temperature of the roughening liquid 260, etc. The surface roughness (Rz) can be 0.01 μm or more and 1.50 μm or less.

  The treatment tank 250 is a batch type water tank. As the roughening liquid 260, for example, a black oxide treatment liquid or a brown oxide treatment liquid that is generally used for roughening the copper foil surface can be used.

  A first adhesive is applied to one side of the plastic film 2 to form a first coating film, and the plastic film 2, the first coating film, the metal foil 4 and the conductive support 240 are arranged in this order, and thermocompression bonding is performed. By doing so, the layers are integrated. Next, the conductive support 240 is peeled off and removed from the obtained laminate, so that the plastic film 2, the first adhesive layer 3 formed on one side of the plastic film 2, and the first adhesive layer 3 are adhered. The shield material 1 provided with the metal foil 4 is obtained.

(Step (b) of forming second adhesive layer)
In the step (b), for example, a step (b1) of manufacturing the substrate 20, a step (b2) of attaching the shield material 1 and the substrate 20 with the second adhesive, and a step of forming the second adhesive layer 30 (b3). ).

  In step (b1), the substrate 20 is manufactured. Examples of the method for manufacturing the substrate 20 include a method in which a part of the metal foil on both surfaces of the double-sided metal foil laminate is removed by etching using a subtractive method or the like to form a predetermined circuit. As a method for producing a double-sided metal foil laminate, in the case of an adhesive type, for example, a known production method such as a dry lamination method or a hot press method may be mentioned, and in the case of an adhesiveless type, for example, casting Known production methods such as a method, a sputtering method, and a plating method can be used.

  In step (b2), the shield material 1 and the substrate 20 are attached with a second adhesive. At this time, the shielding material 1 is arranged so that the plastic film 2 is on the substrate 20 side.

  As a method of pasting with the second adhesive, for example, after the second adhesive is applied to the surface of the plastic film 2 of the shield material 1 to form a coating film (hereinafter sometimes referred to as a second coating film), A method of superimposing one side of the substrate 20 and the shield material 1 and then superposing the remaining surface of the substrate 20 and the shield material 1 in the same manner, or applying a second adhesive to one side of the substrate 20 and applying the second coating After forming the film, the shield material 1 is overlaid on the second coating film so that the plastic film 2 is on the second coating film side, and then the shielding material 1 is overlaid on the remaining surface of the substrate 20 in the same manner. The method etc. are mentioned.

  In step (b3), the second adhesive layer 30 is formed. Thereby, as shown in FIG. 2, the substrate 20, the second adhesive layer 30 formed on the surface of the substrate 20, and the shield material 1 that is bonded onto the second adhesive layer 30 and covers the substrate 20 are provided. As the shield material 1, a substrate 10 with a shield material is obtained in which the plastic film 2 is disposed on the substrate 20 side.

  Examples of the method for forming the second adhesive layer 30 include a method in which the laminated body superposed in step (b2) is subjected to thermocompression bonding, the second coating film is cured and laminated and integrated.

  The temperature at the time of thermocompression bonding is preferably 150 to 180 ° C., the treatment time is preferably 30 to 60 minutes, and the atmosphere is preferably 0.05 to 0.20 MPa.

  Hereinafter, the present invention will be specifically described by way of examples. In addition, this invention is not limited to the following Example.

  In the examples, methods for measuring surface roughness (Rz), thickness, glass transition temperature, and elastic modulus are as follows.

(Surface roughness (Rz))
Using a surface roughness measuring instrument “SURFCOM 1500SD surface roughness measuring instrument” manufactured by Tokyo Seimitsu Co., Ltd., ten-point average roughness (R _ZJIS ) defined by JIS B 0601-2013 was determined.

(Thickness)
The object to be measured was subjected to cross-sectional polishing in the thickness direction, and the thickness was measured using an optical microscope with a measuring instrument “LEXTOLS4100” manufactured by OLYMPUS.

(Glass-transition temperature)
The glass transition temperature (Tg) was measured using a viscoelastic spectrometer “DMS100” manufactured by Seiko Instruments Inc. At this time, measurement was performed with a bending module at a frequency of 10 Hz, and the temperature at which tan δ reached a maximum when the temperature was raised from room temperature to 280 ° C. under a temperature rising rate of 5 ° C./min was defined as the glass transition temperature (Tg).

(Elastic modulus)
The elastic modulus at 25 ° C. was measured using a dynamic viscoelasticity measuring device (“DMS210” manufactured by Seiko Instruments Inc.).

[Example 1]
The following were used for the plastic film 2 and the first adhesive. The metal foil 4 was prepared as follows.

(Plastic film 2)
A PET film “Cosmo Shine A4300” (thickness: 25 μm, glass transition temperature: 80 ° C.) manufactured by Toyobo Co., Ltd. was used.
(First adhesive)
-“JER ST11” manufactured by Mitsubishi Chemical Corporation was used.

(Preparation of metal foil 4)
The electrolytic copper film 4 was produced using the apparatus shown in FIGS. 4A and 4B. The following were used for the insoluble anode 210, the electrolytic solution 220, the conductive support 240, and the roughening solution 260.
<Insoluble anode 210>
“K-500” manufactured by TDK Corporation was used.
<Electrolytic solution 220>
Copper sulfate solution consisting of copper sulfate pentahydrate 150 g / L, sulfuric acid 100 g / L, 3-Mercapto-1-propansulfonic Acid Sodium Salt (MPS) 5 ppm, polyethylene glycol (weight average molecular weight: 2000) 15 ppm, chloride ion 10 ppm ( pH: 7) was used.
<Conductive support 240>
An electrolytic copper foil (thickness: 12 μm, glossy surface roughness Rz: 0.8 μm) was used.
<Roughening liquid 260>
A nickel citrate plating bath (pH: 5) prepared with a composition of nickel sulfate 280 g / L, nickel chloride 45 g / L, and citric acid 21 g / L was used.

First, the conductive support 240 was cleaned by cathodic treatment under conditions of 10% sulfuric acid, temperature: 30 ° C., current density: 5 A / dm ² , treatment time: 20 seconds, and then washed with pure water for 20 seconds. did. Next, an electrolyte solution (pH: 6) for forming a release layer prepared with the composition of nickel sulfate hexahydrate 30 g / L, Na ₂ MoO ₄ dihydrate 3 g / L, and sodium citrate 40 g / L. A release layer having a Ni component on the glossy surface was formed on the surface of the conductive support 240 by electrolysis under conditions of temperature: 30 ° C., current density: 2 A / dm ² , and processing time: 20 seconds. Next, the conductive support 240 is washed with running water for 20 seconds, and then subjected to a temperature of 30 ° C., a pH of 6.0, a current density of 0.5 A / dm ² , and a treatment time of 20 seconds using a copper pyrophosphate plating bath. After the cathode treatment, it was washed with pure water for 20 seconds.

Furthermore, in the electrolytic solution 220, untreated electrolytic copper foil 150 is deposited on the surface of the conductive support 240 by electrolysis under conditions of temperature: 40 ° C., current density: 7 A / dm ² , and electrolytic treatment time: 60 seconds. did. The thickness of the untreated electrolytic copper foil 150 was 2 μm. Thereafter, the untreated electrolytic copper foil 150 was washed with running water for 20 seconds, and then subjected to rust prevention treatment and silane coupling agent treatment by known methods.

Thereafter, untreated electrolysis under conditions of temperature: 50 ° C., current density: 3.0 A / dm ² , and roughening treatment time: 5 seconds in the nickel citrate plating bath roughening solution 260 also serving as rust prevention treatment By performing a roughening treatment on the surface of the copper foil 150, a thin Ni layer (roughening film) was formed on the surface of the untreated electrolytic copper foil 150, and the electrolytic copper foil 4 with the conductive support 250 was obtained. The surface roughness (Rz) of the surface subjected to the roughening treatment of the obtained electrolytic copper foil 4 was 1.30 μm.

<Preparation of sealing material 1>
First, the adhesive which comprises the 1st contact bonding layer 3 was apply | coated to the single side | surface of the plastic film 2, and the 1st coating film was formed. Next, the plastic film 2, the first coating film, the metal foil 4, and the conductive support body 240 are overlapped so that the roughened surface of the electrolytic copper foil 4 with the conductive support body 250 becomes the first coating film side. It was. Next, bonding was performed at 150 ° C. and a pressure of 1.3 MPa while evacuating (50 Torr or less), and aged at 60 ° C. for 7 days. Thereafter, the conductive support 250 was peeled off to obtain the sealing material 1.

The thickness of the sealing material 1 was 35 μm. The thickness of the first adhesive layer 3 was 8 μm.
The elastic modulus at 25 ° C. of the first adhesive layer 3 was 500 GPa. The glass transition temperature of the first adhesive layer 3 was 70 ° C.

[Example 2]
In Example 1, the electrolytic copper foil 4 having a thickness of 8 μm was obtained by setting the electrolytic treatment time to 240 seconds. In addition, “jER 1032H60” manufactured by Mitsubishi Chemical Corporation was used as the first adhesive. Other conditions were the same as in Example 1.

  The thickness of the sealing material 1 was 41 μm. The elastic modulus at 25 ° C. of the first adhesive layer 3 was 50 GPa.

[Example 3]
In Example 1, an electrolytic copper foil 4 having a surface roughness (Rz) of 0.2 μm was obtained by setting the roughening treatment time to 2 seconds. The thickness of the first adhesive layer 3 was 2 μm. Other conditions were the same as in Example 1. The thickness of the sealing material 1 was 29 μm.

[Example 4]
In Example 1, “EXA-830LVP” manufactured by DIC Corporation was used as an adhesive. Other conditions were the same as in Example 1. The elastic modulus at 25 ° C. of the first adhesive layer 3 was 1500 GPa.

[Comparative Example 1]
In Example 1, the electrolytic copper foil 4 having a thickness of 15 μm was obtained by setting the electrolytic treatment time to 480 seconds. Moreover, by making the roughening treatment time 20 seconds, an electrolytic copper foil 4 having a surface roughness (Rz) of 7.0 μm was obtained. The thickness of the 1st contact bonding layer 3 was 15 micrometers. Other conditions were the same as in Example 1. The thickness of the sealing material 1 was 55 μm.

  The board | substrate with a shielding material was produced using the obtained sealing material, and the following evaluation was performed.

<Manufacture of substrate with shield material>
The adhesives for forming the substrate 20 and the second adhesive layer were as follows.
(Substrate 20)
“R-F775” manufactured by Panasonic Corporation was used.
(Adhesive for forming second adhesive layer)
“JER ST11” manufactured by Mitsubishi Chemical Corporation was used.

  First, a second adhesive is applied to one surface of the substrate 20 to form a second coating film, and then the shielding material 1 is overlaid on the second coating film so that the plastic film 2 is on the second coating film side. Combined. Next, after applying the second adhesive to the remaining surface of the substrate 20 in the same manner to form the second coating film, the plastic film 2 is placed on the second coating film side on the second coating film. The shield material 1 was overlapped. Thereafter, lamination was performed by thermocompression bonding under conditions of temperature: 120 ° C., pressure: 0.1 MPa, and processing time: pressure of 10 minutes. Thereby, the board | substrate 10 with a shielding material was obtained.

(Flexibility evaluation)
A bending resistance test specified in JIS C 5016 was performed using a substrate 10 with a shield material of 200 mm × 5 mm. The bending test conditions were a bending radius of 5 mm, a stroke of 50 mm, and a reciprocation count of 100 times. The flexibility of the substrate with shield material 10 was evaluated according to the following criteria.
“◎”: The substrate with shield material 10 is not cracked, chipped or cracked at all.
“◯”: The substrate with shield material 10 is not cracked or chipped, but has a slight crack.
“X”: A crack or chipping occurs in a part of the substrate 10 with the shield material.

(Insulation evaluation)
After leaving the substrate 10 with the shielding material in an environment of 60 ° C. and 90% Rh for 96 hours, a voltage of DC 500 V is applied between the conductor on the surface of the substrate 20 and the metal foil on the surface of the shielding material 1 to insulate. Sex was evaluated according to the following criteria.
“◯”: The insulation resistance between the circuit 22 on the surface of the substrate 20 and the metal foil 4 on the surface of the shield material 1 is 10 ⁶ Ω or more.
“X”: The insulation resistance between the circuit 22 on the surface of the substrate 20 and the metal foil 4 on the surface of the shield material 1 is less than 10 ⁶ Ω.

(Disconnection evaluation)
A bending resistance test specified in JIS C 5016 was performed using a substrate 10 with a shield material in which a wiring pattern with a conductor width / conductor gap of 100 μm / 100 μm was formed on the surface of a substrate 20 of 200 mm × 5 mm. The bending test conditions were a bending radius of 5 mm, a stroke of 50 mm, and a reciprocation count of 100 times. The disconnection evaluation was performed on the shielded substrate 10 according to the following criteria.
“O”: No disconnection.
“×”: There is a disconnection.

  The evaluation results are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 Sealing material 2 Plastic film 3 1st contact bonding layer 4 Metal foil 10 Board | substrate with a shielding material 20 Board | substrate 21 Base film 22 Circuit 30 2nd contact bonding layer 150 Untreated electrolytic metal foil 200 Power supply 210 Insoluble anode 220 Electrolytic solution 230 Processing tank 240 Conductivity Support 250 Treatment tank 260 Roughening liquid 300 Main substrate 310 Outer circuit 400 Conductive adhesive layer

Claims (7)

Plastic film,
A first adhesive layer formed on one side of the plastic film;
A metal foil adhered on the first adhesive layer,
The metal foil comprises an electrolytic metal foil or a rolled metal foil having a thickness of 0.3 μm or more and 9.9 μm or less,
A shielding material, wherein a surface roughness (Rz) of the metal foil facing the first adhesive layer is 0.01 μm or more and 1.50 μm or less.   The shielding material according to claim 1, wherein the first adhesive layer includes at least one resin selected from an acrylic resin, an epoxy resin, and a urethane resin.   The shield material according to claim 1 or 2, wherein the glass transition temperature of the first adhesive layer is lower than the glass transition temperature of the plastic film.   4. The shield material according to claim 1, wherein the first adhesive layer has a thickness of 0.1 μm to 10.0 μm.   The shielding material according to claim 1, wherein the first adhesive layer has an elastic modulus at 25 ° C. of 1000.0 GPa or less. A substrate,
A second adhesive layer formed on the surface of the substrate;
The shield material according to any one of claims 1 to 5, wherein the shield material is bonded onto the second adhesive layer and covers the substrate.
The substrate with a shield material, wherein the shield material is arranged so that the plastic film is on the substrate side. Preparing a shield material in which a metal foil is bonded to one side of a plastic film via a first adhesive layer;
Bonding the plastic film of the shield material and the substrate with an adhesive for forming a second adhesive layer, and forming a second adhesive layer,
The metal foil comprises an electrolytic metal foil or a rolled metal foil having a thickness of 0.3 μm or more and 9.9 μm or less,
The surface roughness (Rz) on the side facing the first adhesive layer of the metal foil is 0.01 μm or more and 1.50 μm or less,
The method for manufacturing a substrate with a shield material, wherein the shield material is disposed such that the plastic film is on the substrate side.

Images