WO2008004399A1 - Bonding resin composition for fluororesin substrates and metal-clad laminates made by using the composition - Google Patents

Abstract

The invention aims at providing a technique which brings about a remarkable improvement in the close adhesion of a fluororesin substrate and a non-coarsened metal foil through easier means and enables the formation of fine-pitch circuits. The aim can be attained by using, as the resin composition for forming the bonding layer for adhesive-bonding a metal foil to a fluororesin substrate, a bonding resin composition for fluororesin substrates which is characterized by comprising 2 to 20 parts by weight of a solvent-soluble polymer component bearing one or more kinds of functional groups selected from among hydroxyl, carboxyl and amino in the molecule and at least 50 parts by weight of an epoxy resin compound consisting of an epoxy resin having a boiling point of 200°C or above and an amine-type curing agent for epoxy resins which has a boiling point of 200°C or above. The invention also provides adhesives for fluororesin substrates which contain the resin composition; an adhesive-covered metal foil (4) which is a laminate constituted of a metal foil (2) and a bonding layer (3); copper-clad laminates made by using the composition; and a process for the production of the laminates.

Description

 Specification

 Fluororesin substrate adhesive resin composition and metal-clad laminate obtained using the fluororesin substrate adhesive resin composition

 Technical field

 [0001] The present invention relates to a fluororesin substrate adhesive resin composition, a fluororesin substrate adhesive using the fluororesin substrate adhesive resin, and the fluororesin substrate adhesive. The present invention relates to a metal-clad laminate, a printed wiring board, and a method for producing the metal-clad laminate. In particular, a fluororesin substrate-adhesive resin composition, which is an adhesive raw material having excellent adhesion to a fluororesin substrate, which is said to be difficult to obtain good adhesion even when bonded to a metal foil, The present invention relates to an adhesive for a fluororesin substrate using the fluororesin substrate-adhesive resin composition.

 Background art

 [0002] Electronic devices such as personal computers and mobile phones in recent years tend to increase the clock frequency at the GHz level in order to enable high-speed communication and high-speed computation. Correspondingly, printed circuit boards are also required to have dielectric properties such as low dielectric loss and low dielectric constant, high-frequency properties such as crosstalk properties, and other heat resistance and durability.

 [0003] Also, in electronic devices such as satellite communication devices, due to the development of satellite broadcasting and satellite communication, in antennas and BS converters, etc., the microwave (30 GHz or lower) frequency band, millimeter waves used for higher-speed information transmission. Considering use in the frequency band (30 GHz to 300 GHz), printed wiring boards with excellent crosstalk characteristics for high frequency circuits have been developed.

 In the applications as described above, it can be expected that the frequency band to be used will further shift to the high frequency band in the future. As the frequency band increases in this way, dielectric properties are particularly important for printed wiring boards. In such applications, fluororesin substrates have been used for insulating layers of printed wiring boards.

[0005] For example, Patent Document 1 describes a dielectric obtained by combining a glass cloth having a low dielectric constant and a low dielectric loss tangent and a fluororesin, and an electrolytic copper foil formed on at least one principal surface of the dielectric. A copper-clad laminate with a dielectric constant of 2.3 (12 GHz) or less and a dielectric loss tangent of 0.00. A fluororesin copper-clad laminate having a characteristic of 1 (12 GHz) or less is disclosed. From this document, it can be understood that the fluororesin base material has excellent dielectric properties and is extremely useful as a material for constituting an insulating layer of a printed wiring board in a high frequency region.

 [0006] However, when a fluororesin base material is used, there is a drawback that the adhesion between the fluororesin base material and the metal foil is weak. In particular, the adhesion after moisture absorption tended to be weakened.

 [0007] In order to improve the adhesion between the fluororesin substrate and the metal foil, Patent Document 2 describes that a fluororesin adhesive impregnation is performed between the fluororesin-impregnated layer in which the fluororesin is impregnated and held in a glass cloth and the metal foil. A printed wiring board provided with a layer is disclosed. The fluororesin adhesion impregnated layer at this time is used to improve the adhesion between the metal foil and the fluororesin impregnated layer immediately below the metal foil by the anchor effect due to the resin characteristics, and to enhance the peel strength. . The fluororesin adhesion impregnation layer preferably uses PTFE as the fluororesin of the fluororesin impregnation layer and PFA as the fluororesin of the fluororesin adhesion impregnation layer. That is, the fluororesin is combined with both the base material and the adhesive layer.

 [0008] In Patent Document 3, any one selected from polyallylsulfone, aromatic polysulfide, and aromatic polyether is used for the purpose of providing a wiring board that can be used with high reliability even under high-temperature and high-humidity conditions. Also disclosed is the use of a fluororesin composition comprising at least one thermoplastic resin and a fluororesin as an insulating layer constituting material of a printed wiring board.

[0009] Furthermore, Patent Document 4 does not improve the adhesion between the fluororesin substrate and the metal foil, but improves the adhesion between the fluororesin substrate and the conductor formed by the screen printing method. For this purpose, the surface of the substrate on which the conductor wiring is to be formed is subjected to a roughening treatment, a plasma treatment, a roughening treatment, a plasma treatment, or a roughening treatment followed by a metal film coating by sputtering. There is disclosed a printed wiring board characterized in that one of the treatments is subjected to one surface treatment.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-307611

 Patent Document 2: WO01 / 003478

 Patent Document 3: Japanese Patent Laid-Open No. 11 199738

Patent Document 4: WO2003 / 103352 Disclosure of the invention

 Problems to be solved by the invention

[0011] However, if the use of printed wiring boards obtained from fluororesin copper-clad laminates is difficult, electronic devices can be made more multifunctional and smaller. It has been requested.

 [0012] And, copper foils manufactured by an electrolytic method or a rolling method have been widely used for the circuit formation. This copper foil is usually subjected to a roughening treatment, an antifungal treatment, and a silane coupling agent treatment on the bonding surface. Depending on the level of the roughening treatment at this time, it is difficult to form a required fine pitch circuit by an etching method. However, if the adhesion between the fluororesin substrate and the copper foil is low, the chemical resistance and moisture absorption resistance against the etching solution and the like are remarkably deteriorated, making it impossible to form a fine pitch circuit. In recent years, copper-clad laminates using FR-4 substrates have been attempted to form fine-pitch circuits, which were previously impossible, using unroughened copper foil. In contrast, conventional fluororesin substrates have poor adhesion between the fluororesin substrate and the metal foil, so when using a non-roughened metal foil, almost no adhesion is obtained, and no roughening occurs. The use of foil was not even considered.

 [0013] In the methods disclosed in Patent Document 2 and Patent Document 3, sufficient adhesion between the fluororesin substrate and the non-roughened copper foil cannot be obtained, and there is a certain limit. As a result, when a heat shock was applied, peeling (delamination phenomenon) occurred between the fluororesin substrate and the circuit formed of the non-roughened copper foil!

 [0014] Therefore, in the market, there has been a demand for a technique capable of remarkably improving the adhesion between the fluororesin substrate and the non-roughened metal foil and forming a fine pitch circuit by a simpler method.

 Means for solving the problem

 [0015] Therefore, the inventors of the present invention, as a result of earnest research, formed an adhesive interface between the fluororesin base material and the metal foil using the resin composition described below, thereby producing a fluororesin-based printed wiring board. This greatly improved the peel strength of the circuit and made it possible to use a non-roughened metal foil. Therefore, the metal foil described below mainly means a non-roughened metal foil. The present invention will be described below.

[0016] Fluororesin substrate adhesive resin composition: Fluororesin substrate adhesive resin according to the present invention The composition is a resin composition for forming an adhesive layer for laminating a metal foil to a fluororesin substrate. The resin composition is soluble in a solvent and has a hydroxyl group as a functional group in the molecule. 2 to 50 parts by weight of a polymer component having one or more of a carboxyl group and an amino group, and an epoxy resin having a boiling point of 200 ° C or higher and an amine epoxy resin curing agent having a boiling point of 200 ° C or higher. It is characterized by containing 50 parts by weight or more of an epoxy resin compound.

[0017] In the resin composition for adhering a fluororesin substrate according to the present invention, the polymer component is selected from the group consisting of a polybulassal resin, a phenoxy resin, an aromatic polyamide resin, a polyether sulfone resin, and a polyamideimide resin. It is preferable to use one or a mixture of two or more.

 [0018] In the resin composition for bonding a fluororesin substrate according to the present invention, the epoxy resin having a boiling point of 200 ° C or higher is bisphenol A type epoxy resin, bisphenol F type epoxy resin, rubber-modified bis. It is preferable to use one or a mixture of two or more selected from the group of phenol A type epoxy resins and biphenyl type epoxy resins.

 [0019] In the fluororesin substrate adhesive resin composition according to the present invention, the amine-based epoxy resin curing agent may be an aromatic polyamine, a polyamide, or an epoxy resin or polyvalent rubonic acid that is polymerized or condensed. It is preferable to use one or more selected from the group of amine adducts obtained by the above method.

 [0020] Adhesive for fluororesin base material: The adhesive for a fluororesin base material according to the present invention is a resin adhesive used for bonding a metal foil to a fluororesin substrate, and the fluororesin base material It is obtained by adding an organic solvent to the adhesive resin composition and mixing it.

 [0021] The adhesive for a fluororesin substrate according to the present invention is one solvent selected from the group consisting of methyl ethyl ketone, cyclopentanone, dimethylformamide, dimethylacetamide, and N-methylbivinylidone. Alternatively, it is preferable to use a mixed solvent thereof.

[0022] Metal foil with adhesive layer: The metal foil with adhesive layer according to the present invention is a metal foil with an adhesive layer provided on the surface of the metal foil with an adhesive layer to the substrate, the adhesive layer comprising the fluororesin. It is formed using a resin adhesive for substrates. [0023] In the metal foil with an adhesive layer according to the present invention, the adhesive layer has a thickness of 0. δ μ μ η

Preferable to be ~ 3 m semi-cured resin layer!

[0024] Further, in the metal foil with an adhesive layer according to the present invention, the adhesive layer of the metal foil with an adhesive layer has a resin flow when measured according to MIL-P-13949G in the MIL standard.

Within 5%! /, It is preferable to have the characteristics!

[0025] Further, in the metal foil with an adhesive layer according to the present invention, the metal foil is copper foil, nickel foil, tin foil, gold foil, silver foil, platinum foil, iron foil, cobalt foil, copper alloy foil, nickel alloy foil. It is preferable to use any of the following strengths: a soot alloy foil, a gold alloy foil, a silver alloy foil, a platinum alloy foil, an iron alloy foil, and a cobalt alloy foil.

[0026] Metal-clad laminate: The metal-clad laminate according to the present invention is a metal-clad laminate obtained by adhering a metal layer to the surface of a fluororesin substrate via an adhesive layer, and the adhesive layer includes: It contains the said resin composition, It is characterized by the above-mentioned.

[0027] Further, the metal-clad laminate according to the present invention is a metal-clad laminate obtained by attaching a metal layer to the surface of a fluororesin substrate via an adhesive layer, and the adhesive layer includes the fluororesin It is formed using the adhesive agent for base materials.

Printed wiring board: The printed wiring board according to the present invention is obtained by etching and etching the metal foil of the metal-clad laminate.

[0029] Method for producing metal-clad laminate: The method for producing a metal-clad laminate according to the present invention is characterized by the following steps A-1 to C1, and for convenience of explanation, Hereinafter referred to as “first manufacturing method”.

 [0030] Step A1: A step of applying an activation treatment to the bonding surface of the fluororesin base material to the metal foil.

 Step B—1: Prepare a fluororesin substrate adhesive, apply this fluororesin substrate adhesive to the surface of the metal foil, and dry it. A process for producing a metal foil with an adhesive layer by forming a 111-thick semi-cured resin layer.

 Process C 1: A process for forming a metal-clad laminate by hot-pressing the adhesive layer surface of the metal foil with an adhesive layer in contact with the laminated surface subjected to the activation treatment of the fluororesin base material .

[0031] The method for producing a metal-clad laminate according to the present invention includes the following steps A-2 to C: It is also possible to adopt one characterized by going through 2. For convenience of explanation, it is hereinafter referred to as “second manufacturing method”.

[0032] Step A-2: A step of applying an activation treatment to the bonding surface of the fluororesin base material to the metal foil.

 Step B-2: Prepare a fluororesin substrate adhesive, apply this fluororesin substrate adhesive to the surface of the releasable plastic film, and dry it. A process for producing an adhesive layer with a releasable plastic film in which a 0.5 to 3 am semi-cured resin layer is in a laminated state.

 Step C2: The semi-cured resin layer of the adhesive layer with a releaseable plastic film is brought into contact with the laminated surface subjected to the activation treatment of the fluororesin base material, and is temporarily bonded to each other, and the releaseable plastic film The step of peeling off and leaving the semi-cured resin layer on the surface of the fluororesin substrate.

 Step D-2: A step of forming a metal-clad laminate by laminating a metal foil on the surface of the semi-cured resin layer provided on the surface of the fluororesin substrate in Step C2 and hot pressing it.

[0033] Furthermore, the method for producing a metal-clad laminate according to the present invention includes the following steps A-3 to C:

It is also possible to adopt one characterized by going through 3. For convenience of explanation, it is hereinafter referred to as “third manufacturing method”.

[0034] Step A—3: A step of applying an activation treatment to the bonding surface of the metal foil of the fluororesin substrate.

 Step B-3: Step of preparing an adhesive for a fluororesin substrate.

 Step C3: Applying the adhesive for the fluororesin base material prepared in Step B-3 to the activated surface of the fluororesin base material and drying it, 0.5 111 to 3111 half thickness A step of forming a cured resin layer.

 Step D-3: A step of forming a metal-clad laminate by laminating a metal foil on the surface of the semi-cured resin layer provided on the surface of the fluororesin substrate in Step C3 and hot pressing it.

[0035] In the above-described method for producing a metal-clad laminate, it is preferable to use any one of a roughening treatment, a plasma treatment, or a combination treatment combining these as the activation treatment. .

 The invention's effect

[0036] The fluororesin substrate-adhesive resin composition according to the present invention has no roughening relative to the fluororesin substrate. It is suitable for forming an adhesive layer when laminating metal foil, and it significantly improves the adhesion between the fluororesin base material and non-roughened metal foil, and the circuit when subjected to a heat shock. The delamination phenomenon can be effectively prevented. When an adhesive layer is to be formed with this fluororesin substrate adhesive resin composition, an organic solvent is added to the fluororesin substrate resin composition to provide an optimal resin flow suitable for layer formation. The resin solid content can be obtained and can be used as an adhesive for a fluororesin substrate.

[0037] Then, it is easy to form an adhesive layer on the surface of the metal foil using the resin adhesive for a fluororesin substrate, and it is possible to provide a metal foil with an adhesive layer for a fluororesin substrate. . At this time, the best adhesion to the fluororesin substrate can be obtained by setting the thickness of the adhesive layer to a semi-cured resin layer of 0.5 m to 3 m. In this case, various non-roughened metal foils can be used as the metal foil, and the metal foil can be widely used without being limited to printed wiring board applications.

 [0038] By using the above resin composition for bonding a fluororesin substrate, a resin adhesive for a fluororesin substrate, and a metal foil with an adhesive layer for a fluororesin substrate, adhesion between the fluororesin substrate and the metal layer is achieved. It is possible to provide a metal-clad laminate excellent in the above. Therefore, by using this metal-clad laminate, it is possible to provide a high-quality printed wiring board.

 [0039] Furthermore, in the method for producing a metal-clad laminate according to the present invention, since the adhesive layer is interposed, the press temperature during hot pressing can be lowered, and the production cost can be reduced. In addition, the adhesion between the fluororesin base material and the metal layer can be more stably improved by applying an activation treatment to the bonded surface of the metal foil of the fluororesin base material in advance.

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0040] Hereinafter, embodiments related to the present invention will be described. In the explanation, each item is explained separately.

[0041] Form of Resin Composition for Adhesion of Fluororesin Base Material: The resin composition for adhesion of a fluororesin substrate according to the present invention is (1) soluble in a solvent and has a hydroxyl group or a carboxyl group in the molecule as a functional group. 2 to 50 parts by weight of a polymer component having one or more amino groups, (2) an epoxy resin having a boiling point of 200 ° C or higher and an amine epoxy resin curing agent having a boiling point of 200 ° C or higher It contains 50 parts by weight or more of a resin blend. here Then, it is a case where the sum total of the said polymer component and an epoxy resin compound is 100 weight part.

 Here, “a polymer component that is soluble in a solvent and has one or more of a hydroxyl group, a carboxyl group, and an amino group in a molecule as a functional group” (hereinafter simply referred to as “polymer component”). Is preferably a mixture of one or two or more selected from the group consisting of a polybulacetal resin, a phenoxy resin, an aromatic polyamide resin, a polyethersulfone resin, and a polyamideimide resin. The polymer component here is required to have the property of being soluble in a solvent. If not possible, it will be difficult to adjust the solid content using a solvent. And when this polymer component strength is less than 3 parts by weight, the hardness after press molding of the copper clad laminate becomes high and brittle, so that toughness cannot be obtained. On the other hand, when the polymer component exceeds 50 parts by weight, the heat resistance is lowered, and it becomes impossible to withstand the press molding temperature of the copper clad laminate, thereby causing resin deterioration. More preferably, the polymer component is 2 to 30 parts by weight. The heat resistance and flexibility as the cured resin are the best.

 [0043] “Epoxy resin having a boiling point of 200 ° C or higher” is selected from the group of bisphenol A type epoxy resin, bisphenol F type epoxy resin, rubber-modified bisphenol A type epoxy resin, and biphenyl type epoxy resin. It is preferable to use one kind or a mixture of two or more kinds. By using a linear (bifunctional) epoxy resin, the adhesion between the fluororesin substrate and the metal foil can be increased. Therefore, the total of the “epoxy resin having a boiling point of 200 ° C or higher” and the “amine-based epoxy resin curing agent having a boiling point of 200 ° C or higher”, which is the main component of this resin composition, is called an epoxy resin compound, and this is 50 weight. It is preferable that it becomes more than part. More preferably, it is used in a blending ratio of 50 to 80 parts by weight. Therefore, when the epoxy resin compound is less than 50 parts by weight, the adhesion between the fluororesin substrate and the metal foil cannot be sufficiently improved, and when it exceeds 80 parts by weight, the fluidity is obtained when a resin solution is obtained. As a result, the range of the resin flow described later cannot be maintained.

[0044] And, as an epoxy resin curing agent, if it is only intended to be cured, amines such as dicyandiamide, imidazoles and aromatic amines, phenols such as bisphenol A and bisphenol A bromide A, etc. All kinds of curing agents such as phenols, phenolic nopolac resins and cresol novolac resins, etc. and acid anhydrides such as phthalic anhydride That power S. However, it is most preferable to use an amine epoxy resin curing agent having a boiling point of 200 ° C. or higher from the viewpoint of significantly improving the adhesion between the fluororesin substrate and the metal foil. If the press molding temperature is around 180 ° C, and the boiling point of the curing agent is around this press molding temperature, the epoxy resin curing agent will boil due to the press molding, and bubbles are likely to be generated in the cured insulating resin layer. . The most stable adhesion can be obtained when an amine epoxy resin curing agent is used to form an adhesive layer between the fluororesin substrate and the metal foil. That is, the “amine-based epoxy resin curing agent having a boiling point of 200 ° C. or higher” is selected from the group of aromatic polyamines, polyamides, and amine adducts obtained by polymerizing or condensing these with epoxy resins or polyvalent carboxylic acids. The case where one kind or two or more kinds are used. More specifically, 4, 4, -diaminodiphenylsulfone, 3, 3, —diaminodiphensulfone, 4,4 diaminodiphenylsulfone, 2,2 bis [4- (4-aminophenoxy) It is preferable to use any one of [Ninole] propane and bis [4- (4-aminophenoxy) phenol] sulfone. In addition, since the amount of the amine-based epoxy resin curing agent added to the epoxy resin is naturally derived from the equivalents, it is not considered necessary to specify the mixing ratio strictly strictly. Therefore, in the present invention, the addition amount of the curing agent is particularly limited!

 [0045] It is also preferable to use a curing accelerator added in an appropriate amount as necessary. Here, the curing accelerator is a tertiary amine, imidazole, urea curing accelerator or the like. In the present invention, the mixing ratio of the curing accelerator is not particularly limited. This is because the curing accelerator is a good one that the manufacturer arbitrarily determines the amount of addition in consideration of the heating conditions during the press working.

[0046] It is also preferable to add a rubbery resin to the resin composition referred to in the present invention. The rubbery resin mentioned here is described as a concept including natural rubber and synthetic rubber, and the latter synthetic rubber includes styrene butadiene rubber, butadiene rubber, butyl rubber, ethylene propylene rubber and the like. Furthermore, when heat resistance is required, it is also useful to selectively use heat-resistant synthetic rubbers such as nitrile rubber, chloroprene rubber, silicon rubber and urethane rubber. Regarding these rubber resins, it is desirable to have various functional groups at both ends so as to react with the polymer component to form a copolymer. [0047] Furthermore, it is also preferable to add the above-mentioned polymer polymer crosslinking agent as necessary. For example, in the case of using a polybulacetal resin as the polymer, the urethane resin is used as a cross-linking material.

 [0048] Assuming that all the components of the resin composition described above are included, when the resin composition is 100 parts by weight, the epoxy resin is 50 parts by weight to 80 parts by weight, and the curing agent is 1 part by weight. -15 parts by weight, curing accelerator 0.01 parts by weight 1.0 parts by weight, polymer component 2 parts by weight to 50 parts by weight, cross-linking agent 1 part by weight to 5 parts by weight, rubber resin 1 part by weight It is preferred to employ a composition in the range of ~ 10 parts by weight. As long as it is included in this composition range, good adhesion between the fluororesin substrate and the metal foil is maintained, and variation in product adhesion is reduced.

 [0049] Form of Fluororesin Substrate Adhesive: Generally, it is difficult to use the resin composition for adhering a fluororesin base as it is to form an adhesive layer. Therefore, an organic solvent is added to and mixed with the fluororesin substrate adhesive resin composition and used as an adhesive for a fluororesin substrate. In such a case, the resin solid content is preferably adjusted to 10 wt% to 40 wt%. When the resin solid content is less than 10 wt%, the viscosity is too low, and even if a resin film for forming an adhesive layer is formed, it flows immediately after coating and it is difficult to ensure film thickness uniformity. On the other hand, when the resin solid content exceeds 40 wt%, it becomes difficult to form a thin resin film with high viscosity.

 [0050] As the organic solvent at this time, any one of methyl ethyl ketone, cyclopentanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, one solvent or a mixed solvent thereof should be used. Is preferred. As the solvent here, a solvent that can dissolve the resin composition is selected. However, when methyl ethyl ketone and / or cyclopentanone is used as a solvent, it is easy to efficiently volatilize and remove by heat at the time of press working in the production of a metal laminate, and also easy to purify volatile gas. In addition, it is easy to adjust the resin solution viscosity suitable for resin film formation. In the case of a mixed solvent of methyl ethyl ketone and cyclopentanone, the mixing ratio is not particularly limited. However, when methyl ethyl ketone is used as a co-solvent for cyclopentanone, the rate of volatilization removal is preferred. Les.

[0051] In the case of a polymer component that is difficult to dissolve in the above methyl ethyl ketone or cyclopentanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. Used as a solvent. In particular, when a solvent obtained by mixing a plurality of these solvents is used, the quality stability of the obtained resin solution tends to be ensured for a long period of time. Even when using a strong or solvent, the resin solid content of the resin solution is preferably 10 wt% to 40 wt% for the same reason.

 [0052] Form of Metal Foil with Adhesive Layer: As shown in FIG. 1, the metal foil with an adhesive layer according to the present invention has a metal foil 4 with an adhesive layer provided with an adhesive layer 3 for a substrate on the surface of the metal foil 2. The adhesive layer is formed by using the resin adhesive for a fluororesin substrate. This forming method will be described later.

[0053] In the metal foil with an adhesive layer according to the present invention, the adhesive layer is a semi-cured resin layer having a thickness of 0. Here, if it is not a semi-cured resin layer, it will not be reflowed by hot pressing, so that the fluororesin substrate and the metal foil cannot be bonded together. The reason why the thin resin layer is formed in this way is to reliably create a state in which the resin flow described below hardly occurs at the time of pressing. When the thickness of this adhesive layer is less than 0. δ πι, it is difficult to make the thickness uniform, and it is difficult to leave a resin layer having a uniform thickness between the fluororesin substrate and the metal foil. Thus, in the surface of a single metal-clad laminate with a workpiece size, the peel strength varies greatly. On the other hand, if the thickness of the adhesive layer exceeds, the good electrical properties of the fluororesin substrate are deteriorated. Note that the thickness of the adhesive layer is a converted thickness when it is assumed that the resin is applied to a completely flat surface per lm ² .

[0054] In the metal foil with an adhesive layer according to the present invention, the adhesive layer of the metal foil with an adhesive layer has a resin flow of 5% or less when measured according to MIL-P-13949G in the MIL standard. It is preferable to have characteristics. Unless the resin flow force is within this range, good adhesion between the fluororesin substrate and the metal foil cannot be obtained. The lower limit is not specified, but it is about 1%. Regarding the resin flow, the thickness of the adhesive layer and the resin solid content of the resin adhesive for the fluororesin substrate used when forming the adhesive layer are factors that determine the characteristics. Of course, resin flow is important. Usually, when laminating a metal foil and a fluororesin substrate, air stagnation may occur at the interface. So, the copper clad laminate Taking the case of manufacturing as an example, a resin flow of about 5mm to 5mm from the end is intentionally caused by an lm ² size copper clad laminate that also serves as an air vent. However, in the case of the adhesive layer used in the present invention, the fact that this resin flow hardly occurs is an important factor for ensuring good adhesion between the fluororesin base material and the metal foil.

[0055] In this specification, the resin flow is determined by the value measured according to MIL-P-13949G of the MIL standard. In other words, in order to ensure the accuracy of resin flow measurement, the adhesive layer is intentionally formed on the surface of the electrolytic copper foil with a thickness of 40 m, and four 10 cm square samples are manufactured. The four 10cm square samples are stacked and bonded together under the conditions of a press temperature of 171 ° C, a press pressure of 14kgf / cm ² and a press time of 10 minutes, and the resin flow at that time is calculated and calculated according to Equation 1. It was. Note that the resin flow of a normal resin-prepared copper foil (40 11 m thick resin layer) is about 20% when using a normal pre-preda.

 [0056] [Equation 1]

_,, Outflow resin weight _{¾ Λ} . Resin flow (%) = 1 0 0

 (Layer weight) (Copper foil weight)

[0057] Further, in the metal foil with an adhesive layer according to the present invention, the metal foil is a copper foil, a nickel foil, a tin foil, a gold foil, a silver foil, a platinum foil, an iron foil, a cobalt foil, a copper alloy foil, or a nickel alloy foil. It is preferable to use any of the following strengths: a soot alloy foil, a gold alloy foil, a silver alloy foil, a platinum alloy foil, an iron alloy foil, and a cobalt alloy foil. That is, it is described with the concept of all metal foils that can be used for electronic materials. All of the metal foils may be obtained by an electrolytic method, obtained by a rolling method, or obtained by a physical vapor deposition method, regardless of the production method. Moreover, there is no special limitation regarding the thickness.

[0058] However, adhesion can be further improved by subjecting the surface of the metal foil to an antifouling treatment, a silane coupling agent treatment, or the like. Accordingly, the metal foil used in the present invention is intended for the one that omits the roughening treatment. However, there is no problem in using a metal foil that has been roughened. Note that the roughening treatment means that the surface of the metal foil is fine. There are no particular restrictions on the method used to deposit metal particles or to chemically treat the surface of the metal foil to form irregularities. In particular, the generally known roughening treatment is a roughening treatment performed by depositing and forming fine copper grains applied to the electrolytic copper foil and the rolled copper foil.

[0059] The antifungal treatment referred to here is appropriately selected according to the type of the fluororesin substrate and is not particularly limited. As the antifouling treatment, either an organic antifouling using benzotriazole, imidazole or the like, or an inorganic fender using zinc, chromate, zinc alloy, nickel alloy or the like may be adopted. In the case of organic fenders, techniques such as dip coating, showering and electrodeposition of organic fenders can be employed. In the case of an inorganic barrier, it is possible to use a method in which the barrier element is deposited on the surface of the copper foil by electrolysis, or a so-called substitution deposition method. In the drawing, the anti-bacterial treatment layer is not particularly described and omitted.

 [0060] The silane coupling agent treatment is carried out using one or two or more of amino-based silane coupling agent, epoxy-based silane coupling agent, and mercapto-based silane coupling agent. It is common. In the silane coupling agent treatment, various types such as the most common epoxy functional silane coupling agent, olefin functional silane, acrylic functional silane, etc. can be used as the silane coupling agent. However, it is particularly preferable to use an amino functional silane coupling agent or a mercapto functional silane coupling agent because the adhesion between the fluorine resin substrate and the metal foil can be further improved. It has been said that the higher the peel strength of printed circuit boards, the better. However, in recent years, circuit peeling during etching has been eliminated by improving the accuracy of the etching technology, and a method for handling printed wiring boards in the printed wiring board industry has been established, eliminating the problem of disconnection peeling caused by accidental circuit catching. It has been. Therefore, in recent years, it is said that if it has a peel strength of at least 0.8 kgf / cm, it can be used practically. 1. If it is at least Okgf / cm, it is said that there is no problem.

[0061] These silane coupling agents will be described more specifically. Mainly coupling agents similar to those used for prepreda glass cloth for printed wiring boards, buttrimethoxysilane, butenyltrimethoxylane, γ-methacryloxyprovir trimethoxy Silane, γ-Aminopropyltriethoxysilane, Ν—β (aminoethyl) _γ —Aminopropyltrimethoxysilane, Ν—3— (4- (3-Aminopropoxy) ptoxy) propyl 3-aminopropyl trimethoxy Silane, imidazole silane, triazine silane, γ mercaptopropyltrimethoxysilane, and the like can be used.

 [0062] The method for treating the silane coupling agent is not particularly limited, such as a commonly used dipping method, showering method, spraying method or the like. In accordance with the process design, a method that allows the metal foil and the solution containing the silane coupling agent to be brought into contact and adsorbed most uniformly can be arbitrarily adopted. The silane coupling agent is used at a temperature of room temperature by dissolving 0.5 to 10 g / l in water as a solvent. When the silane coupling agent concentration is less than 0.5 g / l, the adsorption rate of the silane coupling agent is not suitable for the general commercial basis, and the adsorption is not uniform. Even if the concentration exceeds lOg / 1, the adsorption rate is not particularly high, which is uneconomical. In the drawings, the silane coupling agent-treated layer is not particularly described and is omitted.

 [0063] Form of metal-clad laminate: The metal-clad laminate according to the present invention is a metal-clad laminate obtained by attaching a metal layer to the surface of a fluororesin substrate via an adhesive layer, and the adhesive layer Includes the above resin composition. Further, the adhesive layer is formed using the fluororesin substrate adhesive. Fig. 2 shows the cross-sectional configuration of the metal-clad laminate according to the present invention. Fig. 2 (a) shows a single-sided metal-clad laminate la, Fig. 2 (b) shows a double-sided metal-clad laminate lb, and Fig. 2 (c) shows a 4-layer metal-clad laminate with an inner circuit 9 inside. lc is shown. Therefore, the metal-clad laminate according to the present invention is a state in which the metal foil 2 is bonded to the outer layer that is not related to the layer structure, and the inner layer includes the fluororesin base layer 5 and includes the metal foil. A laminate having an adhesive layer 3 between 2 and a fluororesin substrate layer 5 is referred to.

[0064] Here, FIG. 2 (c) briefly describes a method of manufacturing the four-layer metal-clad laminate lc provided with the inner layer circuit 9 therein. For example, the double-sided printed wiring board 21 is formed by etching the metal layers on both sides of the double-sided metal-clad laminate lb shown in FIG. Then, using a double-sided printed wiring board 21 and a pre-preda 22 such as FR-4, etc., the four-layer metal-clad laminate lc is obtained by laminating as shown in FIG. 3 and hot pressing. Also two pieces Using a double-sided printed wiring board 21 and a fluororesin base material 5 provided on both sides with an adhesive layer 3 using the fluororesin material adhesive according to the present invention, lamination is performed as shown in FIG. By doing so, a four-layer metal-clad laminate lc can be obtained.

 [0065] The fluororesin base material referred to here is PTFE (polytetrafluoroethylene (tetrafluoride)), PFA (tetrafluoroethylene 'perfluoroalkyl butyl ether copolymer), FEP (tetrafluoroethylene.hexafluoropropylene copolymer (4.6 hexafluoride)), ETFE (tetrafluoroethylene.ethylene copolymer), PVDF (polyvinylidene fluoride (2 fluorine)) )), PCTFE (polychlorinated trifluoroethylene (trifluoride)), and at least any one selected from polyallylsulfone, aromatic polysulfide and aromatic polyether as disclosed in Patent Document 3. It is a base material using a fluororesin composed of one kind of thermoplastic resin and fluororesin, and may or may not include a skeleton material such as glass cloth. Moreover, there is no special limitation also about the thickness of this fluororesin base material.

 [0066] Form of Printed Wiring Board: The printed wiring board according to the present invention is obtained by etching the metal foil of the metal-clad laminate. Although the etching process at this time is not particularly limited, an etching resist layer is provided on the surface of the metal foil, the etching pattern is exposed and developed, the resist pattern is formed, and an etching solution capable of dissolving the constituent metal components of the metal foil. In general, the circuit etching is performed.

 [0067] Form of Method for Producing Metal-Clad Laminate: A first method for producing a metal-clad laminate according to the present invention will be described. Hereinafter, step A-1 to step C1 will be sequentially described.

[0068] Step A-1: In this step, an activation treatment is applied to the bonding surface of the metal foil of the fluororesin substrate. The activation treatment referred to here is performed to improve the adhesion between the fluororesin substrate and the adhesive layer, and as a result, improve the adhesion of the metal foil to the surface of the fluororesin substrate. Specifically, this activation treatment is roughening treatment, plasma treatment, or a combination treatment combining them. For the roughening treatment of the fluororesin substrate, a wet or dry blast method, a wet etching method, a dry etching method, or the like can be used. In particular, a wet etching roughening process using a chemical technique often employs a technique called sodium etching. The roughened surface formed by this roughening treatment preferably has an average roughness (Ra) of 20 nm to 100 nm! /. This average roughness (Ra) is less than 20nm In this case, the adhesion between the fluororesin substrate and the adhesive layer cannot be improved. On the other hand, even if the average roughness (Ra) exceeds lOOnm, the effect of improving the adhesion between the fluororesin substrate and the adhesive layer due to the roughening does not increase further.

[0069] The plasma treatment is a treatment in which a plasma stream is generated with an inert gas such as nitrogen gas or argon gas, and the surface of the fluororesin substrate is brought into contact with the plasma stream. The inert gas is decompressed and introduced into the atmosphere, a pair of flat plate electrodes are arranged in parallel, a voltage is applied between the electrodes to generate a plasma stream, and a fluororesin substrate is placed in the plasma stream. Put in and process for a certain time. Alternatively, a plasma stream is generated between the high-frequency electrodes and the like, and a fluororesin substrate is placed in the plasma stream and processed for a certain period of time. Is no particular limitation to the plasma treatment conditions in this case, but the input power (W) and the electrode area (cm ²⁾ power density is calculated from the (W / cm ²⁾ is ^{0. 05W / cm 2 ~; IW} / If cm ² is used, a processing time of 30 seconds to 1 minute is adopted. This plasma treatment time does not significantly improve the adhesion between the fluororesin substrate and the metal foil even if it is unnecessarily long.

[0070] Further, in the case of performing a combined process in which the roughening process and the plasma process are combined, either process may be performed first. FIG. 5 (a) conceptually shows the activated fluororesin substrate 5.

 [0071] Step B-1: In this step, an adhesive for a fluororesin substrate is prepared, and this adhesive for a fluororesin substrate is applied to the surface of the metal foil and dried, so that the surface of the metal foil is coated. A metal foil with an adhesive layer is produced by forming a semi-cured resin layer having a thickness of 0.5 to 111 m. The preparation of the fluororesin substrate adhesive is as described above.

 [0072] Then, the adhesive for a fluororesin base material is applied to the surface of the metal foil 2 and dried, so that a 0.5 m to 3 m thick semi-cured resin layer (drawing) is formed on the surface of the metal foil 2. The metal foil 4 with an adhesive layer shown in FIG. 5 (b) is manufactured by forming the “simply shown as“ adhesive layer 3 ””.

[0073] Step C 1: In this step, as shown in FIG. 5 (c), the bonded surface subjected to the activation treatment of the fluororesin substrate in Step A-1 is obtained in Step B-1. The metal-laminated laminate la shown in FIG. 5 (d) is obtained by laminating the adhesive layer 3 of the metal foil 4 with the adhesive layer in contact with each other and performing hot press molding. There is no particular limitation on the hot pressing conditions at this time. However In the case of the manufacturing method according to the present invention, in the press working using a conventional fluororesin substrate

Pressing force of 260 ° C to 400 ° C or so has been adopted, and press working at a low temperature of around 200 ° C (190 ° C to 220 ° C) is possible. Therefore, there is an advantage that the manufacturing cost can be reduced because the heat energy required for press working is low. The same applies hereinafter.

 [0074] Further, the second method for producing a metal-clad laminate according to the present invention is characterized by going through the following steps A-2 to C2.

 [0075] Step IV-2: In this step, activation treatment is performed on the bonding surface of the metal foil of the fluororesin substrate, which is the same as in the case of the first manufacturing method. Therefore, the description is omitted. FIG. 6 (a) conceptually shows the activated fluororesin substrate 5.

 [0076] Step B-2: In this step, the fluororesin base material adhesive is prepared by the above-described method, and the fluororesin base material adhesive is applied to the surface of the releasable plastic film 7 and dried. Thus, as shown in FIG. 6B, the releasable plastic film and a semi-cured resin layer having a thickness of 0 · 5 111 to 3 111 (shown simply as “adhesive layer 3” in the drawing) An adhesive layer 8 with a releasable plastic film is produced in a laminated state.

 Here, the releasable plastic film is used in the sense of selectively using a film having releasability, and there is no particular limitation on the material, thickness, and the like. Specifically, it is preferable to use a PET film, a thermoplastic fluororesin film, a polyimide resin film, or the like. At this time, with respect to the method of applying the adhesive for the fluororesin base material to the releasable plastic film, an edge coater, a comma coater, a Daravia coater, etc. that are not particularly limited can be used.

 Step C 2: In this step, as shown in FIG. 6 (c), the semi-cured resin of the adhesive layer 8 with the releasable plastic film is applied to the bonded surface on which the fluororesin substrate 5 has been activated. The layers (shown simply as “adhesive layer 3” in the drawing) are brought into contact with each other and are temporarily bonded together, and the releasable plastic film 7 is peeled and removed.

 [0079] Step D-2: In this step, the metal foil 2 is laminated on the surface of the semi-cured resin layer provided on the surface of the fluororesin substrate in Step C2, as shown in FIG. The metal-clad laminate la shown in Fig. 6 (e) is formed by press forming.

[0080] Then, the third method for producing a metal-clad laminate according to the present invention includes the following steps A-3 to It is characterized by passing C3.

[0081] Step A-3: In this step, an activation treatment is performed on the bonding surface of the metal foil of the fluororesin substrate, which is the same as in the case of the first manufacturing method. Therefore, the description is omitted. FIG. 7 (a) conceptually shows the activated fluororesin substrate 5.

Step B-3: In this step, an adhesive for a fluororesin substrate is prepared. Therefore, since the explanation about this adjustment is as described above, the duplicate explanation here is omitted.

Step C 3: In this step, the fluororesin base material adhesive prepared in Step B is applied to the activated surface of the fluororesin base material 5 and dried, so that FIG. )

A semi-cured resin layer (shown simply as “adhesive layer 3” in the drawing) having a thickness of 0.5 m to 3 m is formed. With respect to the method for applying the adhesive for the fluororesin base material at this time, an edge coater, a comma coater, a gravure coater, or the like that has special limitations can be used.

[0084] Step D-3: In this step, a metal foil is formed on the surface of the semi-cured resin layer (shown as "adhesive layer 3" in the drawing) provided on the surface of the fluororesin substrate 5 in Step C3. By laminating 2 and hot press forming, the metal-clad laminate la shown in Fig. 7 (c) is obtained.

In the above description of the method for producing a metal-clad laminate, only a single-sided metal-clad laminate has been described as an example. However, those skilled in the art can easily perform double-sided copper based on the same technical idea. It is possible to manufacture stretched laminates and multilayer copper clad laminates.

 Example 1

 [0086] In this example, a copper clad laminate was produced using the first production method, and the peel strength of the copper foil was measured. Hereinafter, it demonstrates for every process.

 [0087] Step A1: In this step, an activation treatment was performed on the laminated surface of the metal foil of a PTFE fluororesin base material (manufactured by Yodogawa Hitec Co., Ltd.) having a thickness of 0.6 mm. There are three types of activation treatments: metallic sodium treatment, plasma treatment, and combined treatment that sequentially performs metallic sodium treatment and plasma treatment. Three types of fluoropolymer substrates, Sample 1, Sample 2, and Sample 3, were manufactured.

[0088] The metal sodium treatment at this time is performed by extracting fluorine atoms from the surface of the fluororesin substrate by the action of metal sodium or a sodium complex, and generating hydroxyl groups, carbonyl groups, or force loxyl groups on the surface. This is intended to activate the surface of the material. Here, a tetra-etch treatment solution manufactured by Junye Co., Ltd. was used.

[0089] Then, plasma treatment, a vacuum chamber in one, spaced placed parallel to the pair of plate-shaped electrodes, the degree of vacuum was evacuated to 1 X 10- ³ Pa order, a nitrogen gas into the vacuum chamber within a Was adjusted so that the degree of vacuum was 0 · 2 Pa, and a low-temperature plasma stream was generated at a power density of 0 · 12 W / cm ² . Then, plasma treatment was performed by placing the fluororesin base material in this low-temperature plasma stream for 1 minute.

[0090] In the combined treatment in which the metal sodium treatment and the plasma treatment were sequentially performed, the metal sodium treatment and the plasma treatment under the above conditions were sequentially performed.

[0091] The activation treatment described above was performed to obtain the activated fluororesin substrate 5 schematically shown in Fig. 5 (a).

 [0092] Step B-1: Here, 69 parts by weight of epoxy resin, 11 parts by weight of curing agent, 0.2 part by weight of curing accelerator, 15 parts by weight of polymer component, 3 parts by weight of crosslinking agent, 3 parts by weight of rubbery resin A resin composition for adhering a part of the fluorine resin substrate was prepared. Specifically, it is shown in Table 1 below.

 [0093] [Table 1]

[0094] Then, the resin composition shown in Table 1 was adjusted to a resin solid content of 30% by weight using methyl ethyl ketone and dimethylacetamide to obtain an adhesive for a fluororesin substrate. Then, using a gravure coater, this non-roughened electrolytic copper foil (thickness: 18 m, flaw-proofing treatment layer: zinc-nickel alloy layer, silane-bonding agent treatment: (γ-aminopropyltriethoxysilane) was applied to the bonding surface. Then air-dry for 5 minutes and then dry for 3 minutes in a heated atmosphere at 140 ° C to form a semi-cured 1.5 ^ 111 thick semi-cured resin layer (adhesive layer). Thus, a metal foil 4 with an adhesive layer shown in FIG. 5 (b) was produced. [0095] The resin flow of the semi-cured resin layer (adhesive layer) obtained at this time was measured with the above-mentioned adhesive for a fluororesin base material. A copper foil provided on one side was manufactured and used as a resin flow measurement sample. Then, four 10 cm square samples were collected from the resin flow measurement sample, and the resin flow was measured in accordance with the above-mentioned MIL-P-13949G. As a result, the resin flow was 1.5%.

 [0096] Step C 1: In this step, as shown in FIG. 5 (c), the three samples obtained in Step A-1

The adhesive layer 3 of the metal foil 4 with the adhesive layer obtained in Step B-1 is brought into contact with the bonded surface of the fluororesin base material (Sample 1, Sample 2, Sample 3) that has been activated. 3 layers (CL 1 1, CL1 2, CL1-3) shown in Fig. 5 (d) by hot press molding at 200 ° CX for 60 minutes at a pressure of 32 kgf / cm ² I got a board la.

 [0097] Manufacture of a sample for peel strength measurement: An etching resist layer was formed on a copper foil layer of the metal-clad laminate la (CLl-1, CL1-2, CLI-3) using a dry film, The etching pattern for forming a linear circuit for measuring the peel strength on this etching resist layer is exposed and developed, a resist pattern is formed, and the metal components of the metal foil are etched with a copper etching solution. The circuit for measuring the peel strength was formed by removing the resist. A 0.2 mm wide linear circuit is used for normal and hydrochloric acid resistance measurement, and a 0.8 mm wide linear circuit is used for moisture resistance measurement.

 [0098] Then, the peel strength between the fluororesin substrate and the copper foil circuit was measured. Table 2 shows the results. The peel strength referred to in this specification is the strength when the copper foil circuit is peeled from the base material in the 90 ° direction (perpendicular to the substrate). Among them, the normal peel strength is the peel strength measured without any treatment immediately after manufacturing the circuit by etching as described above. The peel strength after heating is the peel strength measured after floating in a solder bath at 260 ° C for 20 seconds and then cooled to room temperature.

[0099] Then, the hydrochloric acid resistance deterioration rate was measured after preparing the test circuit and measuring the normal peeling strength force immediately after the hydrochloric acid treatment described in each table (hydrochloric acid: water = 1: 1 at room temperature). ) Shows how much the peel strength has deteriorated after immersing for 60 minutes. [Degradation rate of hydrochloric acid resistance (%)] = ([Normal peel strength] [After hydrochloric acid treatment] Peel strength]) / [Normal The peel strength] is calculated by the formula of X100.

[0100] In addition, the moisture resistance deterioration rate was determined after the moisture absorption treatment described in each table (after 2 hours in boiling ion exchange water) from the normal peel strength measured immediately after creating a test circuit. This indicates how much the peel strength has deteriorated. [Moisture resistance deterioration rate (%)] = ([normal peel strength] [peeling strength after moisture absorption]) / [Normal peel force S strength] Calculated by the formula of X100. Therefore, the smaller the deterioration rate, the better the adhesion between the fluororesin substrate and the copper foil circuit.

 [0101] [Table 2]

Example 2

 [0102] In this example, a copper clad laminate was manufactured using the second manufacturing method, and the peel strength of the copper foil was measured. Hereinafter, it demonstrates for every process.

 Step A-2: Since this step is the same as that of Example 1, it is omitted. Therefore, three types of fluororesin base material, sample: [, sample 2 and sample 3 were also produced here. Fig. 6 (a) conceptually shows the activated fluororesin base material 5.

 [0104] Step B-2: This step uses the same fluororesin substrate adhesive prepared in Example 1, and uses this fluororesin substrate adhesive as a releasable plastic film 7. Fig. 6 (b) shows that the coating is applied to the surface using a nolem using a gravure coater, air-dried for 5 minutes, and then dried in a heated atmosphere at 140 ° C for 3 minutes. As described above, an adhesive layer 8 with a release plastic film in which the release plastic film and a 1.5 πι semi-cured resin layer (in the drawing, simply indicated as “adhesion layer 3”) are laminated is manufactured. did.

Step C 2: In this step, the semi-cured resin of the adhesive layer 8 with a releasable plastic film as shown in FIG. 6 (c) is applied to the bonded surface of the fluororesin substrate 5 that has been activated. layer (In the drawing, it is simply indicated as “adhesive layer 3”). The layers were brought into contact with each other and temporarily bonded by applying moderate pressure, and the releasable plastic film 7 was peeled and removed.

[0106] Step D-2: In this step, the same roughened copper foil (metal foil) as used in Example 1 was formed on the surface of the semi-cured resin layer provided on the surface of the fluororesin substrate in Step C2. As shown in Fig. 6 (d), two layers are laminated and hot press-molded at 200 ° CX for 60 minutes at a pressure of 32 kgf / cm ² , resulting in three types of layer structure (Fig. 6 (e)) ( CL2-1, CL2 2, CL2 3) metal-clad laminate la.

 [0107] Hereinafter, a sample for measuring the peel strength was produced in the same manner as in Example 1, and the peel strength between the fluororesin substrate and the copper foil circuit was measured. The results are shown in Table 3.

[0108] [Table 3]

 Example 3

 In this example, a copper clad laminate was produced using the third production method, and the peel strength of the copper foil was measured. Hereinafter, it demonstrates for every process.

[0110] Step A-3: Since this step is the same as that of Example 1, it is omitted. Therefore, three types of fluororesin base material, sample: [, sample 2 and sample 3 were also produced here. FIG. 7 (a) conceptually shows the fluororesin substrate 5 that has been activated.

[0111] Step B-3: In this step, the same adhesive for a fluororesin substrate as that prepared in Example 1 was prepared.

[0112] Step C 3: In this step, the fluororesin substrate adhesive prepared in Step B 3 is applied to the activated surface of the fluororesin substrate 5, air-dried for 5 minutes, and then 140 By drying for 3 minutes in a heated atmosphere at ° C, as shown in Fig. 7 (b), a 1.5-thickness semi-cured resin layer (shown as "adhesive layer 3" in the drawing) .) Was formed. Application of the adhesive for the fluororesin substrate at this time was performed using an edge coater. [0113] Step D-3: Here, on the surface of the semi-cured resin layer (shown simply as "adhesive layer 3" in the drawing) provided on the surface of the fluororesin substrate 5 in Step C3, 18 111 By laminating the same copper foil (metal foil) 2 as used in Example 1 of thickness and hot press forming at a pressure of 32 kgf / cm ² at 200 ° C for 60 minutes, Fig. 7 (c) Three types (CL3-1, CL3-2, CL3-3) of metal-clad laminate la having the layer structure shown were used.

 [0114] A sample for measuring the peel strength was produced in the same manner as in Example 1, and the peel strength between the fluororesin substrate and the copper foil circuit was measured. The results are shown in Table 4.

 [0115] [Table 4]

[0116] Looking at the examples described above, in all embodiments, unroughened metal foil is used, but all strengths of normal peel strength and peel strength after heating are 1. Okgf / It is over cm. This can be said to be drastically higher considering that the peel strength between the conventional fluororesin substrate and the metal foil is about 0.8 kgf / cm.

 [0117] In all the embodiments, the hydrochloric acid resistance deterioration rate is within 5%, and the moisture resistance deterioration rate is within 10%. In the case of conventional fluororesin printed wiring boards, considering that the hydrochloric acid resistance deterioration rate is around 10% and the moisture resistance deterioration rate is 15% or more, even if unroughened metal foil is used, In addition, it can be said that the adhesion between the fluororesin substrate and the metal foil is improved.

 Industrial applicability

[0118] With the contents of the present invention described above, the non-roughened metal foil and the fluororesin base material show very high adhesion, and the circuit delamination phenomenon when subjected to heat shock, etc. It can be effectively prevented and a fluororesin copper-clad laminate and a fluororesin printed wiring board can be provided. In addition, since a non-roughened metal foil can be used, a fine pitch pattern can be easily formed even when a circuit is formed by an etching method. Therefore, low dielectric loss It has excellent high frequency characteristics related to dielectric properties such as loss and low dielectric constant, crosstalk characteristics, etc., other heat resistance and durability, excellent adhesion between the circuit and the substrate, and high fine pitch pattern. It will be possible to supply quality fluororesin printed wiring boards to the market at low cost. In addition, the method for producing a metal-clad laminate according to the present invention does not require a new device, can use conventional equipment, and can be pressed at a low temperature. Inexpensive.

 Brief Description of Drawings

 FIG. 1 is a schematic cross-sectional view showing a layer structure of a metal foil with an adhesive layer according to the present invention.

 FIG. 2 is a schematic cross-sectional view showing an example of a layered composition of a metal-clad laminate according to the present invention.

 FIG. 3 is a schematic diagram showing an image of manufacturing a multilayer printed wiring board.

 FIG. 4 is a schematic view showing an image of manufacturing a multilayer printed wiring board.

 FIG. 5 is a flowchart for explaining a manufacturing process of a metal-clad laminate according to the present invention.

FIG. 6 is a flowchart for explaining a manufacturing process of a metal-clad laminate according to the present invention.

FIG. 7 is a flowchart for explaining a manufacturing process of a metal-clad laminate according to the present invention.

 [0120] la, lb, lc metal-clad laminate

 2 Metal foil

 3 Adhesive layer

 4 Metal foil with adhesive layer

 5 Fluororesin substrate layer

 7 Releasable plastic film

 8 Adhesive layer with releasable plastic film

 9 Inner layer circuit

20 circuits Double-sided printed wiring board

Claims

The scope of the claims

 [1] In a resin composition for forming an adhesive layer for bonding a metal foil to a fluororesin substrate,

 The resin composition is soluble in a solvent and contains 2 to 50 parts by weight of a polymer component having one or more of hydroxyl group, carboxyl group, and amino group in the molecule as a functional group, and a boiling point of 200 ° C. 50 parts by weight or more of an epoxy resin composition comprising the above epoxy resin and an amine epoxy resin curing agent having a boiling point of 200 ° C or higher,

 A resin composition for adhering a fluororesin base material, comprising:

[2] The polymer component may be one or a mixture of two or more selected from the group consisting of a polybulacetal resin, a phenoxy resin, an aromatic polyamide resin, a polyether sulfone resin, and a polyamideimide resin. Item 2. The resin composition for bonding a fluororesin substrate according to Item 1.

[3] The epoxy resin having a boiling point of 200 ° C or higher is selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, rubber-modified bisphenol A type epoxy resin, and biphenyl type epoxy resin 1 3. The resin composition for adhering a fluororesin substrate according to claim 1 or claim 2, wherein the resin composition is a seed or a mixture of two or more.

[4] The amine-based epoxy resin curing agent comprises at least one selected from the group of aromatic polyamines, polyamides, and amine adducts obtained by polymerizing or condensing these with epoxy resins or polyvalent carboxylic acids. 4. The resin composition for bonding a fluororesin substrate according to any one of claims 1 to 3.

[5] A resin adhesive used for laminating a metal foil to a fluororesin substrate, wherein an organic solvent is added to the resin composition for a fluororesin substrate according to any one of claims 1 to 4. An adhesive for a fluororesin substrate, characterized by being obtained by mixing them together.

[6] The fluororesin according to claim 5, wherein the organic solvent is methylethyl ketone, cyclopentanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, one solvent, or a mixed solvent thereof. Adhesive for substrate.

[7] In the metal foil with an adhesive layer provided with an adhesive layer on the surface of the metal foil,

The adhesive layer is formed using the resin adhesive for a fluororesin substrate according to claim 5 or 6, wherein the metal foil with an adhesive layer for a fluororesin substrate is provided. Yes

 [8] The metal foil with an adhesive layer for a fluororesin substrate according to claim 7, wherein the adhesive layer of the metal foil with an adhesive layer is a semi-cured resin layer having a thickness of 0.511 to 311 m.

[9] The adhesive layer of the metal foil with an adhesive layer has a characteristic that the resin flow is within 5% when measured according to MIL-P-13949G in MIL standard. 2. Metal foil with an adhesive layer for a fluororesin substrate as described in 1.

[10] The metal foil is copper foil, nickel foil, tin foil, gold foil, silver foil, platinum foil, iron foil, cobalt foil, copper alloy foil, nickel alloy foil, tin alloy foil, gold alloy foil, silver alloy foil, The metal foil with an adhesive layer for a fluororesin substrate according to any one of claims 7 to 9, wherein platinum alloy foil, iron alloy foil, or cobalt alloy foil is used.

[11] A metal-clad laminate C obtained by bonding a metal layer to the surface of a fluororesin substrate via an adhesive layer,

 5. The metal-clad laminate, wherein the adhesive layer includes the resin composition according to any one of claims 1 to 4.

[12] Metal-clad laminate C obtained by bonding a metal layer to the surface of a fluororesin substrate via an adhesive layer

 7. The metal-clad laminate, wherein the adhesive layer is formed using the fluororesin substrate adhesive according to claim 5 or 6.

 [13] A printed wiring board obtained by etching a metal foil of the metal-clad laminate according to claim 11 or 12.

 14. A method for producing a metal-clad laminate according to claim 11 or claim 12, wherein the method comprises the following steps A-1 to C1.

 Step A— 1: A step of applying an activation treatment to the bonding surface of the fluororesin substrate to the metal foil. Step B—1: Prepare a fluororesin substrate adhesive, apply this fluororesin substrate adhesive to the surface of the metal foil, and dry it. A process for producing a metal foil with an adhesive layer by forming a 111-thick semi-cured resin layer.

Step C 1: A metal-clad laminate is obtained by hot pressing and laminating the adhesive layer surface of the metal foil with an adhesive layer against the laminated surface subjected to the activation treatment of the fluororesin base material. Process.

 15. A method for producing a metal-clad laminate according to claim 11 or claim 12, wherein the method comprises the following steps A-2 to C2.

 Step A-2: A step of applying an activation treatment to the bonding surface of the fluororesin substrate to the metal foil. Step B-2: Prepare a fluororesin substrate adhesive, apply this fluororesin substrate adhesive to the surface of the releasable plastic film, and dry it. A process for producing an adhesive layer with a releasable plastic film in which a 0.5 to 3 am semi-cured resin layer is in a laminated state.

 Step C2: The semi-cured resin layer of the adhesive layer with a releaseable plastic film is brought into contact with the laminated surface subjected to the activation treatment of the fluororesin base material, and is temporarily bonded to each other, and the releaseable plastic film The step of peeling off and leaving the semi-cured resin layer on the surface of the fluororesin substrate.

 Step D-2: A step of forming a metal-clad laminate by laminating a metal foil on the surface of the semi-cured resin layer provided on the surface of the fluororesin substrate in Step C2 and hot pressing it.

16. A method for producing a metal-clad laminate according to claim 11 or claim 12, wherein the method comprises the following steps A-3 to D-3.

 Step A—3: Step of activating the bonded surface of the metal foil of the fluororesin substrate. Step B-3: Step of preparing an adhesive for a fluororesin substrate.

 Step C3: Applying the adhesive for the fluororesin base material prepared in Step B-3 to the activated surface of the fluororesin base material and drying it, 0.5 111 to 3111 half thickness A step of forming a cured resin layer.

 Step D-3: A step of forming a metal-clad laminate by laminating a metal foil on the surface of the semi-cured resin layer provided on the surface of the fluororesin substrate in Step C3 and hot pressing it.

[17] The method for producing a metal-clad laminate according to any one of [14] and [15], wherein the activation treatment is any one of a roughening treatment, a plasma treatment, and a composite treatment combining these.