JP2006216572A - Moistureproof coverlay film, and flexible printed wiring board employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moistureproof coverlay film in which steam permeability is very low, high level moistureproofness is ensured stably over a long term, and when a flexible printed wiring board is coated with the moistureproof coverlay film, the negative terminal side on the wiring board can be prevented from becoming basic with steam while preventing stripping or short circuit of wiring. <P>SOLUTION: The moistureproof coverlay film comprises a substrate film of polyimide and a multilayer moistureproof film formed thereon. The multilayer moistureproof film comprises an inorganic film, and an organic thin film containing at least a polyvalent metal salt of polycarboxylic acid based polymer (A) where the area ratio α [peak area S<SB>1</SB>(3,700-2,500 cm<SP>-1</SP>)/peak area S<SB>2</SB>(1,800-1,500 cm<SP>-1</SP>)] of infrared ray absorption spectrum is 2.5 or less, and the peak ratio β [peak A<SB>1</SB>(1,560 cm<SP>-1</SP>)/peak A<SB>2</SB>(1,700 cm<SP>-1</SP>)] of infrared ray absorption spectrum is 1.2 or above. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a moisture-proof coverlay film used for covering a flexible printed wiring board, and a flexible printed wiring board using the same.

  As electronics products become lighter, smaller, thinner, and more functional, demand for printed circuit boards is increasing. Among such printed boards, flexible printed wiring boards have the property of withstanding repeated bending, and can be mounted three-dimensionally in a narrow space, so wiring to electronic devices, cables, Its application is expanding as a composite part with a connector function. Particularly in recent years, COF (Chip on Flex) in which an IC chip is directly mounted on a flexible printed wiring board has been put into practical use, and a flexible printed wiring board has been adopted as an interposer for CSP (Chip Scale Packaging) and MCM (Multi Chip Module). For example, a flexible printed circuit board is used as a semiconductor package constituent material. And a coverlay film is coat | covered for the circuit protection of such a flexible printed wiring board, improvement of a flexibility, moisture resistance, etc.

As such a coverlay film, for example, in JP-A-10-235784 (Patent Document 1), a polyimide film is continuously heated by an infrared or far-infrared heater in a line and dried. The moisture content is set to 0.1% by weight or less, a thermosetting adhesive is applied to one or both sides thereof, a release material is laminated thereon, and a dimensional change rate of the film-release material laminate is applied by 150 degrees. A coverlay film is disclosed in which the measured value after heat treatment for 30 minutes is within ± 0.05% in both the longitudinal direction and the width direction. JP-A No. 2003-149804 (Patent Document 2) discloses a coverlay film of 20 ° C. % insulating between the lines after humidity 24 hours tone at resistance RH, a flexible printed wiring board photosensitive obtained by using a photosensitive dry film resist is not less than 10 ¹³ Omega Burleigh film is disclosed. Further, in Japanese Patent Laid-Open No. 2003-330005 (Patent Document 3), it is made of a synthetic resin having a predetermined first moisture permeability and a predetermined first volume shrinkage rate, covers wiring provided on the substrate, and A first protective layer provided in contact with the first protective layer, a predetermined second moisture permeability smaller than the predetermined first moisture permeability, and a predetermined second volume shrinkage greater than the predetermined first volume shrinkage. And a second protective layer provided so as to be in contact with the substrate and covering the first protective layer so that the first protective layer is not exposed to the outside. Is disclosed. Further, in Japanese Patent Laid-Open No. 2001-15876 (Patent Document 4), a circuit is provided on a flexible substrate film via a first member, and a coverlay film is provided on the circuit via a second member. A flexible printed wiring board is described, and a polyimide film is described as such a flexible substrate film and coverlay film.

However, the coverlay films described in Patent Documents 1 to 4 have not been sufficient in terms of moisture resistance. Therefore, in the flexible printed wiring board covered with such a conventional coverlay film, there has been a problem that the flexible printed wiring board is exposed to water due to long-term use. And in the flexible printed wiring board exposed to water in this way, when energized, there was a problem that a hydroxyl group was generated by electrolysis of water on the negative electrode terminal side and became basic, thereby damaging the wiring board. A flexible printed wiring board covered with a coverlay film by melting the base material of the coverlay film due to the hydroxyl groups generated by electrolysis and opening holes, or creating puff-like irregularities on the base material of the coverlay film There was a possibility of causing failure of electrical appliances using the In addition, since the relative dielectric constant of water is as high as about 80, the circuit inductance changes when the flexible printed wiring board is exposed to water, and the electrical circuit characteristics of communication equipment, measuring equipment, and electronic computers that require high frequency characteristics. Had a great influence on Furthermore, when the flexible printed wiring board is exposed to water, the wiring is peeled off from the flexible printed wiring board and the wiring is cut. Further, when the wiring pitch of the flexible printed wiring board exposed to water is narrow, there is a problem that contact failure is likely to occur when the contact resistance with the wiring terminal increases. Furthermore, in the case where the wiring pitch of the flexible printed circuit board exposed to water is narrow, a fine acicular metal called whisker or whisker from a metal having a higher purity than the wiring base metal present in the electroless plating film on the wiring surface There was also a problem that crystals grew and the wiring was short-circuited.
JP-A-10-235784 JP 2003-149804 A JP 2003-330005 A JP 2001-15876 A

  The present invention has been made in view of the above-described problems of the prior art, and is a coverlay film that has a very low water vapor permeability and can stably exhibit a high level of moisture resistance over a long period of time. A moisture-proof cover lay film capable of sufficiently preventing the negative terminal side on the wiring board from becoming basic due to water vapor when the flexible printed wiring board is coated, and peeling or short-circuiting of the wiring, and It aims at providing the flexible printed wiring board using the same.

  As a result of intensive studies to achieve the above object, the present inventors have found that the hydrophilicity of the polycarboxylic acid polymer (A) of the organic thin film containing at least the polyvalent metal salt of the polycarboxylic acid polymer (A). By laminating a laminated film for a moisture-proof film comprising an organic thin film having an increased density of polymer molecular structure due to salt formation with a functional group or a polyvalent metal and an inorganic film on a polyimide film, water vapor A coverlay film that has a very small permeability and can stably exhibit a high level of moisture resistance over a long period of time. When covering a flexible printed circuit board, the negative terminal side on the circuit board is It has been found that a coverlay film can be obtained that can sufficiently prevent the occurrence of peeling and the occurrence of wiring peeling and short-circuiting, and the present invention has been completed.

That is, the moisture-proof coverlay film of the present invention is a moisture-proof coverlay film provided with a base film made of a polyimide film and a laminated film for a moisture-proof film laminated on one surface of the base film. The laminated film for moisture-proof film is
An inorganic membrane;
It contains at least a polyvalent metal salt of the polycarboxylic acid polymer (A) and has an infrared absorption spectrum area ratio α [peak area S ₁ (3700 to 2500 cm ⁻¹ ) / peak area S ₂ (1800 to 1500 cm ⁻¹ )]. An organic thin film having an infrared absorption spectrum peak ratio β [peak A ₁ (1560 cm ⁻¹ ) / peak A ₂ (1700 cm ⁻¹ )] of 1.2 or more,
It is characterized by having.

  As the moisture-proof coverlay film of the present invention, it is preferable that the organic thin film is laminated on one surface of the base film through the inorganic film.

  Moreover, as the moisture-proof coverlay film of the present invention, it is preferable that the inorganic film is laminated on one surface of the base film via the organic thin film.

  The moisture-proof coverlay film of the present invention includes an organic layer in which the laminated film for moisture-proof film is formed by directly facing and adhering the two organic thin films, and the organic layer It is preferable to include the inorganic film laminated on both surfaces.

  Furthermore, as the moisture-proof coverlay film of the present invention, the laminated film for moisture-proof film is formed by laminating two organic thin films via an adhesive layer, and both surfaces of the organic layer. It is preferable to include the inorganic film laminated on the substrate.

  In the moisture-proof coverlay film of the present invention, the polyvalent metal in the organic thin film is preferably at least one metal selected from the group consisting of zinc, zirconium, copper and nickel.

  In the moisture-proof coverlay film of the present invention, it is preferable that the polyvalent metal is zinc, and the binding energy of zinc by Auger electron spectrum analysis has at least one peak between 496 and 498 eV.

  In the moisture-proof coverlay film of the present invention, the inorganic film is preferably an inorganic oxide vapor deposition film.

  In the moisture-proof coverlay film of the present invention, the inorganic oxide is preferably a silicon oxide.

  The moisture-proof coverlay film of the present invention preferably further includes an adhesive layer laminated on the other surface of the base film.

  The flexible printed wiring board of the present invention is covered with the moisture-proof coverlay film of the present invention.

  According to the present invention, it is a coverlay film that has a very low water vapor permeability and can stably exhibit a high level of moisture resistance over a long period of time. Providing a moisture-proof coverlay film capable of sufficiently preventing the negative terminal side on the substrate from becoming basic and causing peeling and short-circuiting of the wiring, and a flexible printed wiring board using the moisture-proof coverlay film It becomes possible.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

First, the moisture-proof coverlay film of the present invention will be described. That is, the moisture-proof coverlay film of the present invention is a moisture-proof coverlay film provided with a base film made of a polyimide film and a laminated film for a moisture-proof film laminated on one surface of the base film. The laminated film for moisture-proof film is
An inorganic membrane;
It contains at least a polyvalent metal salt of the polycarboxylic acid polymer (A) and has an infrared absorption spectrum area ratio α [peak area S ₁ (3700 to 2500 cm ⁻¹ ) / peak area S ₂ (1800 to 1500 cm ⁻¹ )]. An organic thin film having an infrared absorption spectrum peak ratio β [peak A ₁ (1560 cm ⁻¹ ) / peak A ₂ (1700 cm ⁻¹ )] of 1.2 or more,
It is characterized by having.

(Organic thin film)
The organic thin film according to the present invention contains at least a polyvalent metal salt of the polycarboxylic acid polymer (A), and has an infrared absorption spectrum area ratio α [peak area S ₁ (3700 to 2500 cm ⁻¹ ) / peak area S _2. (1800-1500 cm ⁻¹ )] is 2.5 or less, and the peak ratio β [peak A ₁ (1560 cm ⁻¹ ) / peak A ₂ (1700 cm ⁻¹ )] of the infrared absorption spectrum is 1.2 or more. An organic thin film having gas barrier properties and moisture resistance. In the present invention, the above-described area ratio is simplified and expressed as the infrared absorption spectrum area ratio α, or simply as the area ratio α, or the peak ratio is simplified to reduce the infrared absorption spectrum peak ratio β. Alternatively, it may be simply expressed as a peak ratio β. Furthermore, the gas barrier property referred to in the present invention means having a low oxygen permeability under high humidity conditions. Unless otherwise specified, it refers to the oxygen permeability at a temperature of 30 ° C. and a relative humidity (RH) of 80%.

  When the polycarboxylic acid polymer (A) contained in the organic thin film according to the present invention satisfies the following specific requirements, the organic thin film has excellent gas barrier properties such as oxygen even under high humidity, and is humid. Since it has long-term water resistance even in the natural environment of the tropical region, it can be suitably used as a raw material for organic thin films.

  Here, the specific requirement is that the drying conditions (temperature 30 ° C., relative humidity 0%) of the organic thin film formed from the polycarboxylic acid polymer (A) alone, which is the raw material for the organic thin film according to the present invention. It means that the oxygen transmission coefficient is a specific value or less. Further, by limiting the kind of gas, the measurement atmosphere, and the preparation method of the polycarboxylic acid polymer film, the gas permeability coefficient can be adopted as a variable reflecting the structure of the polymer. The relationship between the molecular structure of the polymer and the gas permeability coefficient is described in Jon Wiley & Sons, Inc. , ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING, VOL. 2, p. 177 (1985).

The polycarboxylic acid polymer (A) used as a raw material for the organic thin film according to the present invention is not particularly limited as long as it is an existing polycarboxylic acid polymer, but the gas barrier property and moisture resistance of the organic thin film according to the present invention are not limited. From the viewpoint of improving the property, the oxygen permeability coefficient measured under dry conditions (30 ° C., relative humidity 0%) of the polycarboxylic acid polymer (A) as a raw material is 100 cm ³ (STP) · μm / ( m ² · day · MPa) or less. Such an oxygen transmission coefficient can be obtained by the following method, for example. That is, a 10% by weight aqueous solution of the polycarboxylic acid polymer (A) was prepared, and a coating film in which a polycarboxylic acid polymer layer having a thickness of 1 μm was formed on a plastic substrate was obtained. The oxygen permeability at 30 ° C. and 0% relative humidity when the coating film is dried is measured. As the plastic substrate, any plastic film whose oxygen permeability is known is used. And if the oxygen permeability of the coating film of the obtained polycarboxylic acid polymer (A) is 1/10 or less with respect to the oxygen permeability of the plastic film used alone as the base material, as described above The measured value of the oxygen permeability measured in this manner can be regarded as the oxygen permeability of the layer of the polycarboxylic acid polymer (A). The oxygen permeability coefficient can be converted to an oxygen permeability coefficient by multiplying the measured value of the oxygen permeability thus obtained by 1 μm.

  As the polycarboxylic acid polymer (A) used as a raw material for the organic thin film according to the present invention, an existing polycarboxylic acid polymer can be used. Is a general term for polymers having two or more carboxy groups. Specifically, a homopolymer using α, β-monoethylenically unsaturated carboxylic acid as the polymerizable monomer, and only α, β-monoethylenically unsaturated carboxylic acid as the monomer component. , At least two types of copolymers thereof, copolymers of α, β-monoethylenically unsaturated carboxylic acid and other ethylenically unsaturated monomers, and intramolecular such as alginic acid, carboxymethylcellulose, pectin, etc. Examples thereof include acidic polysaccharides having a carboxy group. These polycarboxylic acid polymers (A) can be used alone or in admixture of at least two polycarboxylic acid polymers (A).

  Here, as the α, β-monoethylenically unsaturated carboxylic acid, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid and the like are representative. Examples of the ethylenically unsaturated monomers copolymerizable therewith include saturated carboxylic acid vinyl esters such as ethylene, propylene and vinyl acetate, alkyl acrylates, alkyl methacrylates, alkyl itaconates, acrylonitrile, vinyl chloride, Representative examples include vinylidene chloride, vinyl fluoride, vinylidene fluoride, and styrene. Further, when the polycarboxylic acid polymer (A) is a copolymer of an α, β-monoethylenically unsaturated carboxylic acid and a saturated carboxylic acid vinyl ester such as vinyl acetate, saponification is further performed. Thus, the saturated carboxylic acid vinyl ester moiety can be converted into vinyl alcohol for use.

  The polycarboxylic acid polymer (A) used as a raw material for the organic thin film according to the present invention is a copolymer of an α, β-monoethylenically unsaturated carboxylic acid and another ethylenically unsaturated monomer. In some cases, the copolymer composition is preferably an α, β-monoethylenically unsaturated carboxylic acid monomer composition from the viewpoint of improving the gas barrier properties of the organic thin film obtained and the resistance to high-temperature steam and hot water. It is 60 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and most preferably 100 mol%. Thus, as the polycarboxylic acid polymer (A) used as the raw material for the organic thin film according to the present invention, it is preferable to use a polymer composed only of α, β-monoethylenically unsaturated carboxylic acid. Furthermore, when the polycarboxylic acid polymer (A) is a polymer composed only of α, β-monoethylenically unsaturated carboxylic acid, preferred specific examples thereof are acrylic acid, methacrylic acid, itaconic acid, maleic acid. , A polymer obtained by polymerization of at least one polymerizable monomer selected from the group consisting of fumaric acid and crotonic acid, and a mixture thereof. Among the polymers composed only of such α, β-monoethylenically unsaturated carboxylic acids, heavy polymers obtained by polymerization of at least one polymerizable monomer selected from acrylic acid, methacrylic acid, and maleic acid. It is more preferred to use coalescence and / or mixtures thereof, and most preferred to use polyacrylic acid, polymethacrylic acid, polymaleic acid, and mixtures thereof. Also, when the polycarboxylic acid polymer (A) is an acidic polysaccharide other than the polymer of the α, β-monoethylenically unsaturated carboxylic acid monomer, for example, alginic acid can be preferably used.

  The number average molecular weight of the polycarboxylic acid polymer (A) is not particularly limited, but is preferably in the range of 2,000 to 10,000,000, more preferably 5,000, from the viewpoint of the formability of the organic thin film. -1,000,000 are preferred.

  In addition, in the organic thin film concerning this invention, it is possible to mix and use other polymers in the range which does not impair the gas barrier property and moisture resistance of an organic thin film other than a polycarboxylic acid type polymer (A). However, it is preferable to use only the polycarboxylic acid polymer (A) alone.

  In addition, the polyvalent metal contained as a constituent in the polyvalent metal salt of the polycarboxylic acid polymer (A) contained in the organic thin film according to the present invention is a polyvalent metal having a metal ion valence of 2 or more. A single atom. Specific examples of such polyvalent metals include alkaline earth metals such as beryllium, magnesium and calcium, transition metals such as titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper and zinc, and aluminum. be able to. Among such polyvalent metals, it is preferable to use zinc, zirconium, copper or nickel. In addition, when a moisture-proof laminated film is used for an electronic component including a display device, the organic thin film is preferably transparent, and examples of the polyvalent metal contained in such an organic thin film include zinc and zirconium. It is done. Furthermore, the organic thin film may be colored, and examples of the polyvalent metal contained in such an organic thin film include copper.

  Moreover, a polyvalent metal compound (B) is used as a raw material for the polyvalent metal salt contained in the organic thin film according to the present invention. Specific examples of such a polyvalent metal compound (B) include oxides, hydroxides, carbonates, organic acid salts, inorganic acid salts of polyvalent metals, ammonium complexes of polyvalent metals, and polyvalent metals. Examples thereof include metal secondary to quaternary amine complexes and carbonates and organic acid salts of these complexes. Examples of the organic acid salt include acetate, oxalate, citrate, lactate, phosphate, phosphite, hypophosphite, stearate, monoethylenically unsaturated carboxylate, etc. Can be mentioned. Examples of the inorganic acid salt include chloride, sulfate, nitrate and the like. Other than that, an alkyl alkoxide of a polyvalent metal can be used.

  Such polyvalent metal compounds (B) can be used alone or in admixture of at least two polyvalent metal compounds. Among such polyvalent metal compounds (B), divalent metal compounds are preferably used from the viewpoint of improving the gas barrier properties, moisture resistance and manufacturability of the organic thin film. Furthermore, among such polyvalent metal compounds (B), alkaline earth metals, zirconium, cobalt, nickel, copper and zinc oxides, hydroxides, carbonates or alkaline earth metals, zirconium, cobalt, nickel It is preferable to use an ammonium complex of copper and zinc or a carbonate of the complex, magnesium, calcium, zirconium, copper, zinc oxides, hydroxide, carbonate, and zirconium, copper, nickel or zinc ammonium. More preferably, a complex and a carbonate of the complex are used.

  In addition, a metal compound composed of a monovalent metal, for example, a monovalent metal salt of a polycarboxylic acid polymer (A) was mixed or contained within a range that does not impair the gas barrier property and moisture resistance of the organic thin film according to the present invention. Can be used as is. The preferable addition amount of such a monovalent metal compound is 0.2 chemical equivalent or less with respect to the carboxy group of the polycarboxylic acid polymer (A) from the viewpoint of gas barrier properties and moisture resistance of the organic thin film. is there. The monovalent metal compound may be partially contained in the molecule of the polyvalent metal salt of the polycarboxylic acid polymer.

  The form of the polyvalent metal compound (B) used as a raw material for the organic thin film according to the present invention is not particularly limited. However, as will be described later, in the organic thin film according to the present invention, a part or all of the polyvalent metal compound (B) forms a salt by ionic bond with the carboxy group of the polycarboxylic acid polymer (A). Yes.

  Therefore, when the polyvalent metal compound (B) that does not participate in carboxylate formation is present in the organic thin film according to the present invention, the polyvalent metal compound (B) is granular from the viewpoint of the transparency of the organic thin film, A smaller particle size is preferred. Also, in preparing a solution or dispersion for producing an organic thin film according to the present invention described later, the polyvalent metal compound is granular in terms of efficiency during preparation and obtaining a more uniform solution or dispersion, The smaller the particle size, the better. The average particle diameter of the polyvalent metal compound is preferably 5 μm or less, more preferably 1 μm or less, and most preferably 0.1 μm or less.

  As described above, the organic thin film according to the present invention includes at least the polyvalent metal salt of the polycarboxylic acid polymer (A), measures a specific region of the infrared absorption spectrum, and has an area ratio α of 2.5 determined from this. And the peak ratio β is 1.2 or more. The organic thin film according to the present invention having such characteristics is satisfactory in gas barrier properties such as oxygen and moisture resistance.

Next, the area ratio α [peak area S ₁ (3700 to 2500 cm ⁻¹ ) / peak area S ₂ (1800 to 1500 cm ⁻¹ )] of the infrared absorption spectrum of the organic thin film will be described.

In the present invention, the area ratio α of the infrared absorption spectrum is substituted as an index representing the amount of water in the organic thin film. Although the state of moisture in the organic thin film is not clear, the moisture in the organic thin film according to the present invention refers to the state of being adsorbed in the organic thin film, and is referred to as adsorbed water. The O-H stretching vibration caused by moisture gives a wide absorption in the infrared light wave number region of 3700-2500 cm- ¹ . Therefore, in the present invention it was defined the peak area of the infrared absorption spectrum of 3700～2500Cm ^-1 peak area _S 1 and (3700~2500cm ^-1). Peak area _S 1 (3700~2500cm ^-1) is a straight line connecting two points of the absorbance of the absorbance and 2500 cm ^-1 in 3700 cm ^-1 as the baseline, can be determined by area integration ranging 3700~2500cm ^-1.

Further, the C═O stretching vibration attributed to the carboxy group (—COOH) in the polycarboxylic acid polymer (A) has an absorption maximum in the vicinity of 1700 cm ^{−1 in} the infrared light wave number region of 1800 to 1600 cm ^−1. Gives a peak with Salts of a carboxyl group (-COO ^-) C = O stretching vibration attributable to provide a peak having an absorption maximum in the vicinity of 1560 cm ^-1 in the infrared wave number range of 1600~1500cm ^-1.

Such a peak attributed to a carboxy group (—COOH) and a salt of a carboxy group (—COO ⁻ ) is a characteristic peak of the organic thin film according to the present invention. Therefore, the area of the infrared absorption spectrum of 1800 to 1500 cm ⁻¹ including this peak is a characteristic peak area of the organic thin film according to the present invention. In the present invention, this area is defined as a peak area S ₂ (1800-1500 cm ⁻¹ ). Peak area _S 2 (1800~1500cm ^-1) is a connecting it straight two points absorbance absorbance and 1500 cm ^-1 in 1800 cm ^-1 as the baseline, can be determined by area integration of a range of 1800～1500Cm ^-1 .

From the above, the ratio of the peak area _S 1 of the infrared absorption spectrum (3700~2500cm ^-1) and the peak area of the infrared absorption spectrum _S 2 _(1800~1500cm ^-1), i.e., the peak area _S 1 (3700~2500cm ^-1 ) / Peak area S ₂ (1800-1500 cm ⁻¹ ) is defined as the area ratio α of the infrared absorption spectrum, and is used as an index representing the amount of water in the organic thin film. In the present invention, the area ratio α of the infrared absorption spectrum is 2.5 or less, preferably 0.01 or more and 2.3 or less, and more preferably 0.01 or more and 2.0 or less. When the area ratio α exceeds 2.5, the moisture resistance is insufficient.

Specifically, in the present invention, the infrared absorption spectrum is measured by transmission method, ATR method (total reflection attenuation method), KBr pellet method, diffuse reflection method, photoacoustic method (PAS method), etc. the calculated peak area S ₁ and the peak area S _2, obtains the ratio of the two. As a typical measurement condition example, using a laminate in which the organic thin film according to the present invention is formed on a base material as a sample, using the ATR method, and using KRS-5 (Thallium Bromide-Iodide) as an ATR prism, Examples include measurement at an incident angle of 45 degrees, a resolution of 4 cm ⁻¹ , and an integration count of 30 times.

In the present invention, the peak ratio β [peak A ₁ (1560 cm ⁻¹ ) / peak A ₂ (1700 cm ⁻¹ )] of the infrared absorption spectrum of the organic thin film is the same as that of the polycarboxylic acid polymer (A) in the organic thin film. Used as an index representing the degree of metal salt formation with the valent metal compound (B). The peak A ₁ (1560 cm ⁻¹ ) constituting the peak ratio β of the infrared absorption spectrum is the absorption peak of the infrared absorption spectrum of C═O stretching vibration in the vicinity of 1560 cm ⁻¹ attributed to the carboxyl group salt (—COO ⁻ ). Area or peak height. That is, usually carboxylate (-COO ^-) C = O stretching vibration attributable to provide an absorption peak having an absorption maximum in the vicinity of 1560 cm ^-1 in the infrared wave number range of 1600~1500cm ^-1. Peak _A 1 (1560cm ^-1) is a straight line connecting two points of the absorbance and absorbance at 1500 cm ^-1 in 1600 cm ^-1 as the baseline, the peak area from the area integration in the range of 1600~1500cm ^-1, 1600~1500cm ^{- The} peak height can be obtained from the height of the absorption maximum in the range of ¹ .

Further, the peak _A 2 constituting the peak ratio beta (1700 cm ^-1), said the peak _A 1 (1560cm ^-1) is separate and independent infrared absorption peak, 1700 cm attributed to a carboxy group (-COOH) ^{- It is} the peak area or peak height of the infrared absorption spectrum of C = O stretching vibration near ¹ . That is, normally, C═O stretching vibration attributed to a carboxy group (—COOH) gives an absorption peak having an absorption maximum in the vicinity of 1700 cm ^{−1 in} the infrared light wave number region of 1800 to 1600 cm ⁻¹ . Peak _A 2 (1700 cm ^-1), the peak area of the straight line connecting two points from the area integral of the scope of the 1800～1600Cm ^-1 as the baseline absorbance of absorbance and 1600 cm ^-1 of the 1800cm ^{-1, 1800~1600cm - The} peak height can be obtained from the height of the absorption maximum in the range of ¹ . The absorbance of the organic thin film is proportional to the amount of chemical species having infrared activity present in the organic thin film. Therefore, the ratio of the peak of the infrared absorption spectrum, that is, peak A ₁ (1560 cm ⁻¹ ) / peak A ₂ (1700 cm ⁻¹ ) is defined as the peak ratio β of the infrared absorption spectrum. It can be used as a measure representing the quantitative ratio of the salt of a carboxy group forming a salt (—COO ⁻ ) and a free carboxy group (—COOH).

The peak ratio β of the infrared absorption spectrum of the organic thin film according to the present invention is 1.2 or more and 10,000 or less. From the viewpoint of moisture resistance of the organic thin film, the peak ratio β is preferably 2.0 or more and 10,000 or less. More preferably, it is 4.0 or more and 10,000 or less. The absorbance baseline of the infrared absorption spectrum has a slight fluctuation related to the measurement limit. From the measurement limit related to the baseline of the absorbance peak A ₁ (1560 cm ⁻¹ ) using the infrared absorption of C═O stretching vibration around 1560 cm ⁻¹ attributed to the carboxyl group salt (—COO ⁻ ), the peak ratio β The upper limit is 10,000. A large peak ratio β (degree of ionization) means that a salt of a free carboxy group (—COO ⁻ ) is constrained by complex formation, and an absorbance peak A ₁ (1560 cm ⁻¹ ) is small.

Furthermore, when the organic thin film according to the present invention is mixed with a metal compound composed of a monovalent metal within a range not impairing the oxygen gas barrier property and moisture proof property, a monovalent metal salt of carboxylic acid (—COO ⁻ C = O stretching vibration attributable to) gives an absorption peak having an absorption maximum in the vicinity of 1560 cm ^-1 in the infrared wave number range of 1600~1500cm ^-1. Therefore, in this case, two C═O stretching vibrations derived from the carboxylic acid monovalent metal salt and carboxylic acid polyvalent metal salt in the infrared absorption peak are included. Also in such a case, as described above, the peak ratio β [peak A ₁ (1560 cm ⁻¹ ) / peak A ₂ (1700 cm ⁻¹ )] is a carboxy group polyvalent metal salt (—COO ⁻ ) and a free carboxy group. It is used as it is as a scale representing the amount ratio of (—COOH).

  The infrared absorption spectrum for obtaining the peak ratio β can be measured using, for example, FT-IR2000 manufactured by PERKIN-ELMER.

  Specifically, the infrared absorption spectrum of the organic thin film according to the present invention is measured by transmission method, ATR method (total reflection attenuation method), KBr pellet method, diffuse reflection method, photoacoustic method (PAS method), etc. The peak height (at the maximum absorption wave number) or peak area of the absorption spectrum is measured, and the ratio between the two is obtained.

As a typical measurement condition example, the organic thin film is peeled off from the laminated film for the moisture-proof film according to the present invention in which the organic thin film and the inorganic film are laminated, and this surface is exposed to the specimen of the organic thin film. In the total reflection infrared analysis method (also referred to as ATR method), KRS-5 (Thallium Bromide-Iodide) is used as the ATR prism, and the measurement is performed at an incident angle of 45 degrees, a resolution of 4 cm ⁻¹ , and 30 integrations. Can be mentioned. For the infrared absorption spectrum measurement method using FT-IR, refer to, for example, Ms. Tasumi Ms. Editor, “Basics and Practice of FT-IR”.

  Moreover, as an organic thin film concerning this invention, it is preferable that the said polyvalent metal is zinc and has the at least 1 peak between 496-498 eV in the binding energy by the Auger electron spectrum analysis of zinc.

  Thus, the more suitable conditions of the organic thin film concerning this invention can be derived using Auger electron spectrum analysis. Here, such Auger electron spectrum analysis is also referred to as X-ray photoelectron analysis (XPS) when the excitation energy source of atoms is X-rays. In such Auger electron spectrum analysis, for example, when attention is paid to zinc, the stoichiometric or non-stoichiometric binding state of zinc can be known from the value of the binding energy. The binding state of complex formation can also be known. When X-rays are used as an excitation energy source in such Auger electron spectrum analysis focusing on zinc, the inner electrons of zinc are ionized by X-ray irradiation to generate vacancies, and electrons at the upper level. Falls and the zinc turns into a stable state. At this time, such an energy difference between levels is transferred to another electron and emitted. The emitted electrons are called Auger electrons. If the energy difference is emitted as X-rays, the X-rays are characteristic X-rays. In the case where zinc is used as the polyvalent metal contained in the organic thin film according to the present invention, when Auger electron spectrum analysis is performed, the L inner-shell electrons of zinc are ionized by the irradiated X-rays to generate vacancies in the L-shell. Then, the M-shell electron in one upper orbital transitions to the L shell, and the N-shell electron in one upper orbital further transitions to the M shell. The present inventors have found that the magnitude of Auger electron emission in the Zn-LMN transition process corresponding to the process of such electron transition is positively correlated with the moisture resistance of the organic thin film. It was. That is, the Auger electron energy of the Zn-LMN transition process is 496 to 498 eV, and having at least one peak between these energies is positively correlated with the moisture resistance of the organic thin film. In addition, it does not restrict | limit especially as a measuring apparatus used for such an analysis, A well-known measuring apparatus can be used suitably, Specifically, using product name Quantera SXM by PHI, etc. is mentioned.

  The organic thin film according to the present invention (hereinafter simply referred to as an organic thin film) is excellent in gas barrier properties such as oxygen even under high humidity.

In addition, the organic thin film according to the present invention is characterized in that it has excellent moisture barrier properties as well as gas barrier properties such as oxygen. That is, the moisture resistance of the organic thin film referred to in the present invention means that the water vapor permeability is 3 g / (m ² · day) or less, preferably 0.3 g / (m ² ) in an atmosphere at a temperature of 40 ° C. and a relative humidity of 90%. Day) or less (90% relative humidity on the water vapor supply side). When this value exceeds 3 g / (m ² · day), a laminated film for a moisture-proof film excellent in moisture resistance intended by the present invention cannot be obtained.

The density of the organic thin film according to the present invention is preferably 1.80 g / cm ³ or more, more preferably 1.80~2.89g / cm ^3, 1.85~2.89g / More preferably, it is cm ³ . When an organic thin film having a density of less than 1.80 g / cm ³ is used, a moisture-proof laminated film having a target moisture-proof performance due to insufficient moisture-proof property tends not to be obtained. On the other hand, in the organic thin film having a density exceeding 2.89 g / cm ³ , the amount of the polyvalent metal compound to be used increases and it becomes difficult to form the organic thin film after coating. The density of such an organic thin film can be measured according to JIS K7112 (a method for measuring the density and specific gravity of plastic).

(Inorganic film)
Although it does not restrict | limit especially as an inorganic film concerning this invention, It is preferable that an inorganic film is an inorganic vapor deposition film, and it is preferable that the said inorganic vapor deposition film consists of an inorganic oxide vapor deposition film. Specifically, as an inorganic material used for forming such an inorganic film, aluminum (Al), aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO _x ; x = 1 to 2), Examples thereof include silicon oxynitride (SiO _x N _y ; x = 0.6 to 0.8, y = 0.7 to 0.9). As examples of the inorganic oxide, in view of transparency, it is particularly preferable to use silicon oxide (SiO _x). By using such an inorganic vapor deposition film as the inorganic film, the resulting laminated film for moisture-proof film has high gas barrier properties and moisture-proof properties.

The inorganic film according to the present invention is an inorganic film having excellent gas barrier properties such as oxygen even under high humidity. The inorganic film according to the present invention has an oxygen permeability of 500 cm ³ (STP) / (m ² · day · MPa measured at 40 ° C. and a relative humidity of 90% (RH) when the thickness of the inorganic film is 1 μm. ) Or less, more preferably 100 cm ³ (STP) / (m ² · day · MPa) or less.

The inorganic film according to the present invention is characterized in that it has excellent gas barrier properties such as oxygen and moisture resistance. The inorganic film according to the present invention preferably has a water vapor permeability of 15 g / (m ² · day) or less in an atmosphere of a temperature of 40 ° C. and a relative humidity of 90% when the thickness of the inorganic film is 1 μm. More preferably, it is 3 g / (m ² · day) or less. This is because when the value exceeds 15 g / (m ² · day), there is a tendency that a laminated film for a moisture-proof film excellent in moisture resistance intended by the present invention cannot be obtained.

(Laminated film for moisture barrier film)
The laminated film for a moisture-proof film according to the present invention includes the organic thin film and the inorganic film. In such a laminated film for a moisture-proof film, the configuration is not particularly limited except that the organic thin film and the inorganic film are provided, and how the organic thin film and the inorganic film are laminated. Also good.

  In such a laminated film for moisture-proof film, the thickness of one organic thin film is not particularly limited, but from the viewpoint of formability and handling properties when forming a laminated film for moisture-proof film, the thickness of one organic thin film is The thickness is preferably 0.001 μm to 200 μm, more preferably 0.01 μm to 100 μm, and particularly preferably 0.1 μm to 10 μm. In such a laminated film for moisture-proof film, when the thickness of one organic thin film is less than 0.001 μm, it becomes difficult to form the organic thin film, and stable production tends to be impossible. On the other hand, when the thickness of the organic thin film exceeds 200 μm, coating is difficult, and there is a tendency for problems to occur in manufacturing.

  Moreover, the thickness of the inorganic film in the laminated film for moisture-proof film is not particularly limited, but the thickness of the inorganic film is 0.01 μm to 100 μm from the viewpoint of moldability and handling properties when forming the laminated film for moisture-proof film. The thickness is preferably 0.1 μm to 10 μm. If the thickness of the inorganic film is less than 0.01 μm, it tends to be difficult to form the inorganic film, and stable production cannot be performed. On the other hand, when the thickness of the inorganic film exceeds 100 μm, it tends to be difficult to stably produce a laminated film for a moisture-proof film.

Further, such a laminated film for a moisture-proof film has a water vapor transmission rate of 0.02 g / (m at 40 ° C. and 90% relative humidity after standing for 250 hours under pre-humidification conditions at 60 ° C. and 90% relative humidity. ² · day) or less is preferable.

  Further, the laminated film for a moisture-proof film according to the present invention includes an organic layer formed by directly facing and adhering two organic thin films, and the inorganic layer laminated on both sides of the organic layer. A laminated film for a moisture-proof film provided with a film, or an organic layer formed by laminating two organic thin films via an adhesive layer, and the inorganic film laminated on both surfaces of the organic layer; The laminated film for moisture-proof film provided with can be suitably used.

  In such a laminated film for a moisture-proof film, the organic layer is formed by laminating the two organic thin films directly or via an adhesive layer. Therefore, even when a micro pinhole is formed in the thickness direction of one organic thin film in the organic layer, since another organic thin film is laminated, it is possible to prevent the micro pin holes from being connected, Deterioration of gas barrier properties and moisture resistance due to micro pinholes in the layer is prevented, and it becomes possible to stably maintain a high gas barrier property and moisture resistance in the moisture-proof laminated film.

  Moreover, in such a laminated film for a moisture-proof film, an inorganic film having a high moisture-proof property is laminated on both surfaces of the organic layer. Therefore, such a laminated film for moisture-proof film can exhibit higher moisture-proof property and gas barrier property. Moreover, since the relatively soft organic layer is covered with a relatively hard inorganic film, the laminated film for a moisture-proof film according to the present invention is a laminated film for a moisture-proof film even when an external force such as bending or impact is applied. The gas barrier property and moisture resistance of the film do not deteriorate.

  The thickness of the adhesive layer is not particularly limited, but is preferably 0.1 to 100 μm from the viewpoint of preventing gas barrier properties and moisture resistance of the resulting laminated film for moisture-proof film from being lowered. More preferably, it is 10-10 micrometers. If the thickness of the adhesive layer is less than 0.1 μm, adhesion of the organic thin film tends to be difficult, and if it exceeds 100 μm, coating is difficult, and a problem tends to occur when manufacturing a laminated film for moisture-proof film.

(Polyimide film (base film))
In the present invention, the polyimide film used as the substrate film is not particularly limited, and a known polyimide film can be appropriately used. As such a polyimide film, it is preferable that thickness is 10-200 micrometers, and it is more preferable that it is 30-100 micrometers. If the thickness of the polyimide film is less than the above lower limit, the heat resistance during soldering tends to be insufficient, while if it exceeds the upper limit, it tends to be difficult to handle during the assembling work.

(Dampproof coverlay film)
The moisture-proof coverlay film of the present invention comprises the moisture-proof laminated film laminated on one surface of the base film made of the polyimide film.

Furthermore, such a moisture-proof coverlay film has a water vapor transmission rate of 0.02 g / (m at 40 ° C. and 90% relative humidity after standing for 250 hours under pre-humidification conditions at 60 ° C. and 90% relative humidity. ² · day) or less is preferable.

  As such a moisture-proof coverlay film of the present invention, the moisture-proof coverlay film (I) in which the organic thin film is laminated on one surface of the substrate film via the inorganic film, the substrate film Moisture-proof coverlay film (II) in which the inorganic film is laminated via the organic thin film on one surface of the substrate, and the two organic thin films directly opposed to one surface of the base film A moisture-proof cover lay film (III) comprising the above-mentioned laminated film for moisture-proof film, comprising: an organic layer formed in close contact with the organic layer; and the inorganic film laminated on both surfaces of the organic layer; An organic layer formed by laminating two organic thin films via an adhesive layer on one surface of the base film, and the inorganic film laminated on both sides of the organic layer The above moisture-proof film laminate Moisture coverlay film with Irumu (IV) are preferred.

  Such a moisture-proof coverlay film may be a laminate in which other layers are further laminated. For example, it is possible to laminate one or more layers for the purpose of imparting abrasion resistance, glossiness, heat sealability, strength or further moisture resistance to a moistureproof coverlay film. It is done.

  Moreover, as such a moisture-proof cover-lay film, it is preferable to further include an adhesive layer laminated on the other surface of the base film.

  The material of the adhesive that forms such an adhesive layer is not particularly limited, and a resin that is usually used for dry lamination or the like can be used. Moreover, although it does not restrict | limit especially as such an adhesive agent, It is preferable to use a urethane type adhesive agent, a polyester-type adhesive agent, an acrylic adhesive agent, or an epoxy-type adhesive agent. Furthermore, such a urethane adhesive, polyester adhesive, acrylic adhesive and epoxy adhesive have a Vicat softening point of 50 from the viewpoint of improving the moisture resistance of the moisture-proof coverlay film of the present invention. Adhesives having a temperature of from C to 140C are preferred, and adhesives having a temperature of from 50C to 98C are more preferred. Here, the Vicat softening point of the adhesive is a softening temperature in a state where the adhesive is cured. The Vicat softening point can be measured according to JIS K-7206. Such adhesives can be used alone or in combination of two or more.

(Method for manufacturing moisture-proof coverlay film)
Hereinafter, preferred embodiments for producing the moisture-proof coverlay film of the present invention will be described.

  First, the solution or dispersion liquid (coating liquid) used when forming the said organic thin film is demonstrated. As such a solution or dispersion (coating solution), either a polycarboxylic acid polymer (A), a polyvalent metal compound (B), a volatile base (C) or an acid (D). And a solution or dispersion liquid (coating liquid) containing a solvent.

  The polycarboxylic acid polymer (A) and the polyvalent metal compound (B) used as raw materials here are as described above. Since the polycarboxylic acid polymer (A) and the polyvalent metal compound (B) easily react in an aqueous solution and form a non-uniform precipitate, the polycarboxylic acid polymer (A) and the polycarboxylic acid polymer (A) In order to obtain a uniform coating solution composed of water as a valent metal compound (B) and a solvent, either volatile base (C) or acid (D) is mixed with water as a solvent.

  As such a volatile base (C), ammonia, methylamine, ethylamine, dimethylamine, diethylamine, triethylamine, morpholine, and ethanolamine are used. Among such volatile bases (C), ammonia is preferably used from the viewpoint of improving the moisture resistance of the organic thin film to be formed. As the acid (D), hydrochloric acid, acetic acid, sulfuric acid, oxalic acid, citric acid, malic acid, tartaric acid and other inorganic acids and organic acids are used.

  In preparing the solution or dispersion (coating liquid), the blending amount of the polyvalent metal compound (B) relative to the amount of the polycarboxylic acid polymer (A) is from the viewpoint of gas barrier properties and moisture resistance of the organic thin film. It is preferably 0.5 chemical equivalent or more, and more preferably 0.8 chemical equivalent or more with respect to all the carboxy groups in the polycarboxylic acid polymer (A). Furthermore, in addition to the above viewpoint, it is preferably 10 chemical equivalents or less, particularly preferably in the range of 1 chemical equivalent or more and 5 chemical equivalents or less, from the viewpoints of moldability and transparency of the organic thin film. Further, from the viewpoint of setting the peak ratio β of the infrared absorption spectrum of the obtained organic thin film to 1.2 or more (preferably 2.0 or more, more preferably 4.0 or more), a polycarboxylic acid polymer ( It is preferable that the compounding quantity of the polyvalent metal compound (B) with respect to the quantity of A) is 0.5-10 chemical equivalent with respect to all the carboxy groups in a polycarboxylic acid type polymer (A). Here, the chemical equivalent is a certain amount of an element (a simple substance) or a compound determined based on chemical reactivity. Since the chemical equivalent in the present invention is a chemical equivalent to the carboxy group in the polycarboxylic acid polymer (A), one chemical equivalent is a base that neutralizes the amount of one equivalent carboxy group acting as an acid. Say quantity. Here, the base is a polyvalent metal constituting the polyvalent metal compound (B).

  The amount of the volatile base (C) necessary for obtaining a uniform mixture solution or dispersion (coating solution) is 1 chemical equivalent to the carboxy group in the polycarboxylic acid polymer (A). It is. However, when the polyvalent metal compound is cobalt, nickel, copper, zinc oxide, hydroxide, carbonate, the volatile base (C) of 1 chemical equivalent or more is added, so that the metal A transparent and uniform solution which forms a complex with the volatile base (C), and which comprises the polycarboxylic acid polymer (A), the polyvalent metal compound (B), the volatile base (C), and water as a solvent. can get. A suitable addition amount of the volatile base (C) is 1 chemical equivalent to 60 chemical equivalents, and further 2 chemical equivalents to 30 chemical equivalents with respect to all carboxy groups in the polycarboxylic acid polymer (A). The following is preferable. When the addition amount is less than 1 chemical equivalent, it is difficult to obtain a uniform solution (coating solution). Further, when a zinc compound is used as the polyvalent metal compound, from the viewpoint of producing a laminated film for a moisture-proof film in which the binding energy of the Auger electron spectrum analysis of zinc has at least one peak between 496 and 498 eV. Is preferably 2 to 120 mol of the volatile base (C) per 1 mol of the zinc compound, particularly when the volatile base (C) is ammonia, 4 mol per 1 mol of the zinc compound. It is preferable to blend ~ 60 mol.

  On the other hand, when the acid (D) is used, the amount of the acid (D) necessary for obtaining a uniform mixture solution or dispersion (coating solution) is the amount of carboxy in the polycarboxylic acid polymer (A). It is preferably 1 chemical equivalent or more and 60 chemical equivalents or less and 2 chemical equivalents or more and 30 chemical equivalents or less with respect to the group. If this amount is less than 1 chemical equivalent, it is difficult to obtain a uniform solution (coating solution). On the other hand, if it exceeds 60 chemical equivalents, there is a problem in the production (film formation) of the film. As the acid (D), hydrochloric acid is preferably used. Further, when a zinc compound is used as the polyvalent metal compound, from the viewpoint of producing a laminated film for a moisture-proof film in which the binding energy of the Auger electron spectrum analysis of zinc has at least one peak between 496 and 498 eV. Is preferably 2 to 120 moles of acid (D) per mole of zinc compound.

  Moreover, when obtaining such a coating liquid, there is no special order in the mixing order of raw materials. Specific examples of the solvent used include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, Examples include heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate and butyl acetate. It is preferable to use water in view of problems such as waste liquid treatment during coating and the possibility that the solvent may remain in the film. For example, in water added as a solvent, polyacrylic acid (obtained in the form of an aqueous solution) as a polycarboxylic acid polymer (A), ammonia (in an aqueous solution state) as a volatile base (C), a polyvalent metal compound Zinc oxide (powder) can be added in this order as (B) and mixed with an ultrasonic homogenizer to obtain a coating solution. The amount of water as a solvent is appropriately adjusted by a combination with other additives so as to suit the coating suitability of the coating apparatus. The solvent may be a single type or a mixture.

  In addition to the above components, a resin, a softener, a stabilizer, a film forming agent, an antiblocking agent, an adhesive, and the like can be appropriately added to the solution or dispersion (coating solution). In particular, it is preferable to mix and use a resin that is soluble in the solvent system used for the purpose of improving the dispersibility and coating properties of the polyvalent metal compound present in excess. Preferable examples of the resin include resins used for coating materials such as alkyd resin, melamine resin, acrylic resin, nitrified cotton, urethane resin, polyester resin, phenol resin, amino resin, fluorine resin, and epoxy resin. The total amount of polyvalent metal salt, polyvalent metal compound, resin, and other additives of the polycarboxylic acid polymer (A) in the coating solution is 1% to 50% by weight from the viewpoint of coating suitability. A range is preferable.

  As such a solution or dispersion, a polycarboxylic acid polymer (A), a polyvalent metal compound (B), a volatile base (C), and ammonium carbonate (E) are mixed with water as a solvent. The resulting solution or dispersion can also be used. Ammonium carbonate (E) is an amount of 1 chemical equivalent or more with respect to all the carboxy groups of the polycarboxylic acid polymer (A) in the state where the polyvalent metal compound (B) is in the state of a polyvalent ammonium carbonate carbonate complex. It is added to prepare a uniform solution containing the polyvalent metal. The amount of ammonium carbonate (E) added to the polyvalent metal compound (B) is a molar ratio, that is, the number of moles of ammonium carbonate (E) / the number of moles of the polyvalent metal compound (B) is from 0.05 to 0.05. It is in the range of 10, preferably in the range of 1-5. When the molar ratio is less than 0.05, it is difficult to obtain a uniform solution (coating solution) containing a polyvalent metal salt in an amount exceeding 1 chemical equivalent with respect to all carboxy groups of the polycarboxylic acid polymer (A). If it exceeds 10, a problem occurs in the formation of an organic thin film. In the following description, a coating liquid using water as a solvent will be described as an example with a polycarboxylic acid polymer (A), a polyvalent metal compound (B), a volatile base (C) or an acid (D), and a solvent. When ammonium carbonate (E) is used, the same consideration can be made unless otherwise specified.

  Next, in order to describe a suitable production method for producing the moisture-proof coverlay film of the present invention, first, an embodiment for producing the moisture-proof coverlay film (IV) will be explained.

[Method for producing moisture-proof coverlay film (IV)]
The manufacturing method of the moisture-proof coverlay film (IV) includes (1) a step of forming an inorganic film on the surface of the base film (inorganic film-forming base film), and (2) an organic thin film on the surface of the inorganic film. A process comprising a step of obtaining two formed films (organic-inorganic laminated film), and a step of (3) laminating two organic thin films via an adhesive layer (a step of obtaining a moisture-proof coverlay film (IV)). It is.

(1) Step of forming an inorganic film on the surface of the base film The method for forming the inorganic film on the surface of the base film (polyimide film) is not particularly limited, and silicon oxide, aluminum oxide, aluminum, chip And a method of forming a thin film made of an inorganic compound such as silicon nitride or silicon oxynitride or a metal compound by a vapor deposition method. As such a vapor deposition method, there is a physical vapor deposition method, for example, a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like. Further, as the sputtering method, a direct current or high frequency sputtering method using a desired material for a target and using an inert gas such as argon or neon as a sputtering gas may be used. Furthermore, the resistance heating vapor deposition method is a method in which a desired material is vapor-deposited by resistance heating, and an inorganic film is formed on the surface of a substrate disposed oppositely. The electron beam vapor deposition method is a desired method. This material is vapor-deposited by an electron beam heating technique, and an inorganic film is formed on the surface of the base material arranged to face each other. By forming the inorganic film in this manner, it is possible to impart high transparency, gas barrier properties and moisture resistance to the resulting laminated film for moisture-proof film. And in this invention, an inorganic film formation base film can be obtained in this way.

(2) A step of obtaining two films in which an organic thin film is formed on the surface of an inorganic film,
In the step of obtaining two organic thin films (organic / inorganic laminated films) on which inorganic films are laminated, the solution or dispersion (on the inorganic films of the two inorganic film-forming substrate films formed as described above) By coating and drying a coating liquid), two organic thin films (organic-inorganic laminated films) on which inorganic films are laminated are obtained.

  As a method for coating the coating liquid on the inorganic film, a known coating method can be used without any particular limitation, and it is performed using dipping or spraying, and a coater, a printing machine, or a brush. Coaters, types of printing machines, and coating methods include direct gravure method, reverse gravure method, kiss reverse gravure method, offset gravure method, gravure coater, reverse roll coater, micro gravure coater, air knife coater, dip coater, bar coater A comma coater, a die coater, or the like can be used.

  In the present invention, the coating thickness (wet) in the state (wet) immediately after coating the solution or dispersion on the inorganic film is preferably 0.02 μm to 1 mm, preferably 0.5 μm to 500 μm. It is more preferable that On the other hand, when the coating layer is dried under heating, the coating thickness (dry) of the solution or dispersion is preferably 0.001 μm to 1 mm, and preferably 0.01 μm to 100 μm. Is more preferable. A desired thickness can be obtained by coating and drying repeatedly 1 to 4 times so as to obtain such a dry thickness.

  On the other hand, as the above-mentioned coating thickness (dry), when the thickness exceeds 5 μm, a value measured from a film cross section using a transmission normalsky differential interference microscope manufactured by Olympus Optical Co., Ltd. is used. Moreover, when this thickness is 5 micrometers or less, the value measured using Otsuka Electronics Co., Ltd. product name MCPD-2000 of the instant multiphotometry system is used.

  In the present invention, the viscosity of the solution or dispersion in a state immediately before coating the solution or dispersion on the inorganic film can be adjusted as appropriate.

  The method of evaporating and drying the solvent after applying the coating liquid on the surface of the inorganic film is not particularly limited. A method using natural drying, a method of drying in an oven set to a predetermined temperature, or a dryer attached to the coater, such as an arch dryer, a floating dryer, a drum dryer, an infrared dryer, or the like can be used. The drying conditions can be arbitrarily selected as long as the base material, the polyvalent metal salt of the polycarboxylic acid polymer (A), and other additives are not damaged by heat.

  In the layer comprising the polycarboxylic acid polymer (A), polyvalent metal compound (B), volatile base (C) or acid (D) on the inorganic film, the polyvalent metal compound (B) is an unreacted molecule. , A polyvalent metal salt with a polycarboxylic acid polymer (A), and a metal complex salt with a polycarboxylic acid. Here, the metal complex salt means a complex of cobalt, nickel, copper, zinc, zirconium or the like and a volatile base. Specific examples of the metal complex salt include zinc and copper tetraammonium complex salts. In this way, the solution or dispersion is applied onto the inorganic film and dried to form an organic thin film.

  And the organic thin film laminated | stacked on the surface of an inorganic film is heat-processed at the temperature of the range of 60 to 400 degreeC, Preferably 100 to 300 degreeC, More preferably, 150 to 250 degreeC, On the surface of an inorganic film An organic thin film can be formed. If it is in the said temperature range, there will be no special restriction | limiting in the case of heat processing. Usually, the heat treatment is preferably performed in an inert gas atmosphere under a pressure of 0.1 to 600 MPa, more preferably 0.1 to 100 MPa, preferably 0.1 to 3000 minutes, more preferably 1 to 2000 minutes. Is called. When the heat treatment temperature exceeds 400 ° C. or the heat treatment time exceeds 3000 minutes, it is difficult to obtain a target film having oxygen gas barrier properties and moisture resistance, and there is a problem from the viewpoint of production. When the heat treatment temperature is less than 60 ° C. or when the heat treatment time is less than 0.1 minutes, moisture is not sufficiently removed, and there is a tendency for problems to occur particularly from the viewpoint of moisture resistance. Moreover, the organic thin film in the laminated film for moisture-proof film obtained more reliably has an area ratio α of the infrared absorption spectrum of 2.5 or less (preferably 0.01 to 2.3, more preferably 0.01 to 2. From the viewpoint of setting to 0), it is preferable to perform heat treatment under conditions of 60 to 400 ° C. under 0.1 to 600 MPa. If the heat treatment temperature is less than the lower limit, moisture tends to be not sufficiently removed, and if the heat treatment temperature exceeds the upper limit, a black to brown pyrolyzate tends to be generated due to thermal decomposition of the resin constituting the organic thin film.

  There are no particular restrictions on the heat treatment method. The heat treatment temperature may be changed a plurality of times, and the heat history may be given by raising the temperature stepwise. The heat treatment apparatus is not particularly limited. For example, the heat treatment can be performed by a continuous heating apparatus such as an atmospheric pressure oven, an autoclave under pressure, a press machine, or a floating furnace. Examples of the heat treatment method include hot air injection, air floating, infrared radiation, microwave irradiation, and high frequency dielectric heating. At the stage of heat treatment, the volatile base (C) or acid (D) or ammonium carbonate (E) is either volatilized or becomes a salt, leaving traces in the film, but affecting the performance of the film. Absent.

(3) Step of laminating two organic thin films via an adhesive layer In step (3), the organic thin film surfaces of the two organic inorganic laminated films obtained as described above are bonded via an adhesive layer. The moisture-proof coverlay film (IV) is obtained by laminating.

  The adhesive used for forming such an adhesive layer is the same as the adhesive used for forming the adhesive layer.

  Moreover, it does not restrict | limit especially as a method of apply | coating an adhesive agent to the organic thin film surface of an organic inorganic laminated film, A well-known coating method can be used, immersion (dipping), a spray, a coater, a printing machine, or It is possible to use a brush. Coaters, types of printing machines, and coating methods include direct gravure method, reverse gravure method, kiss reverse gravure method, offset gravure method, gravure coater, reverse roll coater, micro gravure coater, air knife coater, dip coater, bar coater A comma coater, a die coater, or the like can be used. In addition, when applying the adhesive, the adhesive may be applied to both organic thin film surfaces of the two organic thin films, and one of the two organic thin films You may apply an adhesive only to the surface. Furthermore, it is preferable that the coating thickness when the adhesive is applied to the organic thin film is sufficient to realize a suitable thickness of the above-described adhesive layer.

  In addition, the method for adhering the two organic thin film surfaces to each other is not particularly limited, and a known method can be used as appropriate, and a dry laminating method, an extrusion laminating method, a hot melt laminating method, or the like can be used. Is possible.

  Thus, by laminating the organic thin film surfaces through the adhesive layer, the base film / inorganic film / organic thin film / adhesive layer / organic thin film / inorganic film / base film were laminated in this order. A moisture-proof coverlay film (IV) can be obtained.

  Next, an embodiment of an apparatus for producing a moisture-proof coverlay film (IV) suitable for carrying out the steps (2) and (3) for producing the moisture-proof coverlay film (IV) described above, This will be described in detail with reference to the drawings. In the following description and drawings, the same or corresponding elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

  FIG. 1 is a schematic view showing an embodiment of an apparatus for producing a moisture-proof coverlay film (IV).

  The manufacturing apparatus shown in FIG. 1 includes a feeding device 1, and the feeding device 1 includes an inorganic film forming substrate in which an inorganic film forming base film 3 manufactured according to the manufacturing process (1) described above is wound in a roll shape. A material film roll 2 is installed.

  Moreover, the manufacturing apparatus shown in FIG. 1 includes a corona discharge system 4 and a gravure roll 5 in the direction in which the inorganic film-forming base film 3 fed from the feeding apparatus 1 travels, and part of the gravure roll 5 is The solution 6 of the mixture containing the polycarboxylic acid polymer (A), polyvalent metal compound (B), volatile base (C), and solvent prepared as described above is in contact. Furthermore, the manufacturing apparatus shown in FIG. 1 includes a first drying furnace 7 in the direction in which the inorganic film-forming base film 3 coated with the solution 6 travels.

  Moreover, the manufacturing apparatus shown in FIG. 1 includes two lines configured in the order of the feeding apparatus 1, the corona discharge system 4, the gravure roll 5, and the first drying furnace 7 as described above. The laminating apparatus 8 is further arranged after the first drying furnace 7.

  Further, the manufacturing apparatus shown in FIG. 1 includes an organic / inorganic laminated film that has passed through the first drying furnace 7 and an organic / inorganic laminated film that has been applied with an adhesive through the laminating apparatus 8 (hereinafter referred to as “adhesive layer-forming laminated film”). The heating roll 9, the second drying furnace 10, the accumulator 11, and the winding device 12 are provided in the traveling direction.

  When manufacturing a laminated film for a moisture-proof film using such a production apparatus shown in FIG. 1, first, as a process for obtaining an organic-inorganic laminated film, an inorganic film-forming substrate film roll 2 is set in the feeding apparatus 1. Then, the inorganic film forming base film 3 is fed out. And the corona discharge process is made | formed by the surface of the inorganic film | membrane of the extended inorganic film formation base film 3 passing the corona discharge system 4 extended | stretched. The inorganic film-forming base film 3 subjected to such corona discharge treatment is guided to the gravure roll 5, and the solution 6 is applied on the surface of the inorganic film. In addition, since the surface of the inorganic film of the inorganic film forming base film 3 is subjected to the corona discharge treatment as described above, it is easy to apply the solution 6 uniformly. And the inorganic film formation base film 3 with which the solution 6 was coated is guide | induced to the 1st drying furnace 7, and heat processing is made | formed. Such an operation is performed simultaneously in two lines, and two organic-inorganic laminated films in which an organic thin film is laminated on the surface of the inorganic film are obtained.

  Next, in the present embodiment, a process for obtaining a moisture-proof coverlay film (IV) will be described. First, of the two organic / inorganic laminated films obtained as described above, an adhesive is applied to the organic thin film surface of one of the organic / inorganic laminated films using a laminating apparatus 8 to form an adhesive layer-formed laminated film. obtain. Thereafter, the organic thin film surface of the other organic-inorganic laminated film and the adhesive layer surface of the adhesive layer-forming laminated film are pressure-bonded using a heating roll 9. By performing such pressure bonding, a moisture-proof cover lay film (IV) laminated in the order of base film / inorganic film / organic thin film / adhesive layer / organic thin film / inorganic film / base film can be obtained. And the moisture-proof cover-lay film (IV) crimped | bonded by the heating roll 9 is guide | induced to the 2nd drying furnace 10, and is heat-processed. In addition, between the 1st drying furnace 7 and the heating roll 9, as needed, surface treatment of the organic thin film surface of an organic inorganic laminated film by corona discharge or a normal pressure plasma (not shown) in order to raise the effect of pressure bonding. )). Further, the moisture-proof coverlay film (IV) subjected to such heat treatment passes through the accumulator 11 and is wound up into a roll by the winding device 12 (moisture-proof coverlay film roll 13). Thus, in this embodiment, a moisture-proof coverlay film (IV) can be obtained.

  As mentioned above, although suitable embodiment of the apparatus for manufacturing a moisture-proof coverlay film (IV) was described, the apparatus for manufacturing a moisture-proof coverlay film (IV) is not limited to the said embodiment. Absent. For example, the embodiment described above is an apparatus for manufacturing the moisture-proof cover lay film of the present invention by a series of operations, but a process for manufacturing an adhesive layer-forming laminated film and an organic-inorganic laminated film and a moisture-proof film using the same The process of manufacturing the laminated film may be performed separately using a separate apparatus.

  As mentioned above, although the method of manufacturing a moisture-proof coverlay film (IV) was demonstrated, the method for manufacturing the moisture-proof coverlay film of this invention is not restricted to said manufacturing method.

[Method for producing moisture-proof coverlay film (I)]
The manufacturing method of the moisture-proof coverlay film (I) includes (1a) a step of forming an inorganic film on one surface of the base film (step of obtaining an inorganic film-forming base film), and (2a) the surface of the inorganic film. It is a production method including a step of forming an organic thin film thereon (a step of obtaining a moisture-proof coverlay film (I)).

  Such a manufacturing process (1a) is the same method as the process (1) in the manufacturing method of the moisture-proof coverlay film (IV). Moreover, a manufacturing process (2a) is the same method as the process (2) in the manufacturing method of the said moisture-proof cover-lay film (IV). In this way, a moisture-proof coverlay film (II) laminated in the order of base film / inorganic film / organic thin film can be obtained.

[Method for producing moisture-proof coverlay film (II)]
The manufacturing method of the moisture-proof coverlay film (II) includes (1b) a step of forming an organic thin film on the surface of the base film (step of obtaining an organic thin film forming base film), and (2b) on the surface of the organic thin film. This is a production method including a step of forming an inorganic film (a step of obtaining a moisture-proof coverlay film (II)).

(1b) The process of forming an organic thin film on the surface of a base film The said base material by applying and drying the said solution or dispersion liquid (coating liquid) on the surface of a base film (polyimide film) An organic thin film is formed on the surface of the film. The method of applying and drying such a coating solution is the same method as described in step (2) in the method for producing the moisture-proof coverlay film (IV).

(2b) Step of forming an inorganic film on the surface of the organic thin film The method of forming an inorganic film on the surface of the organic thin film obtained as in (1b) is the production of the moisture-proof coverlay film (IV). The method is similar to the method described in the step (1) of the method. Thus, the moisture-proof coverlay film (II) laminated in the order of the substrate / organic thin film / inorganic film can be obtained.

[Method for producing moisture-proof coverlay film (III)]
The manufacturing method of the moisture-proof coverlay film (III) includes (1c) a step of forming an inorganic film on the surface of the base film (inorganic film forming base film), and (2c) an organic thin film on the surface of the inorganic film. It is a production method including a step of obtaining two formed films (organic-inorganic laminated film), and a step (3c) of adhering two organic thin films (a step of obtaining a moisture-proof coverlay film (III)).

  Such a manufacturing process (1c) is the same method as the process (1) of the manufacturing method of the moisture-proof coverlay film (IV). The production process (2c) is also basically the same method as the process (2) in the production method of the moisture-proof coverlay film (IV). However, the present embodiment is different in that the heat treatment in the step (2) is not performed.

(3c) Step of adhering two organic thin films In step (3c), the organic thin film surfaces of the two organic / inorganic laminated films obtained as described above are directly opposed to each other and are adhered. Thus, a moisture-proof coverlay film (III) can be produced.

  There is no particular limitation on the method of directly facing the organic thin film surfaces of the two organic / inorganic laminated films and bringing them into close contact with each other, and a known method can be used as appropriate. As such a method, specifically, there is a method in which the other surfaces of the two organic thin films in which the inorganic film is laminated on one surface are directly opposed to each other by using a heating roll. It is done. In addition, as a method for performing such pressure bonding, a method using a high-frequency induction heating roll or a resistance heating roll can be cited. Further, when performing such pressure bonding, in order to obtain the flatness of the film, Expanding rolls and dancer rolls can be appropriately arranged before and after. In this manner, the two organic thin films are directly opposed to each other, so that the moisture proof laminated in the order of base film / inorganic film / organic layer (organic thin film 1 / organic thin film 2) / inorganic film / base film. The coverlay film (III) can be obtained.

In addition, when the organic thin film surfaces of the two organic-inorganic laminated films are directly opposed to each other and pressure-bonded, using a heating roll or the like, under a temperature condition of 60 to 500 ° C., 0.5 KPa to 1 × The pressure is preferably 10 ⁶ MPa, more preferably 100 K to 300 ° C., and more preferably 1 KPa to 1 MPa.

  And the obtained moisture-proof cover-lay film (III) is heat-processed at the temperature of the range of 60 to 400 degreeC, Preferably it is 100 to 300 degreeC, More preferably, it is 150 to 250 degreeC. If it is in the said temperature range, there will be no special restriction | limiting in the case of heat processing. Usually, the heat treatment is preferably performed in an inert gas atmosphere under a pressure of 0.1 to 600 MPa, more preferably 0.1 to 100 MPa, preferably 0.1 to 3000 minutes, more preferably 1 to 2000 minutes. Is called. When the heat treatment temperature exceeds 400 ° C. or the heat treatment time exceeds 3000 minutes, it is difficult to obtain a target film having oxygen gas barrier properties and moisture resistance, and there is a problem from the viewpoint of production. When the heat treatment temperature is less than 60 ° C. or when the heat treatment time is less than 0.1 minutes, moisture is not sufficiently removed, and there is a tendency for problems to occur particularly from the viewpoint of moisture resistance. In addition, the organic thin film in the obtained moisture-proof coverlay film (III) more reliably has an infrared absorption spectrum area ratio α of 2.5 or less (preferably 0.01 to 2.3, more preferably 0.01). It is preferable to heat-process on the conditions of 60-400 degreeC under 0.1-600 MPa from a viewpoint of setting it as -2.0). If the heat treatment temperature is less than the lower limit, moisture tends not to be removed sufficiently. If the heat treatment temperature exceeds the upper limit, black or brown pyrolyzate tends to be generated due to thermal decomposition of the resin constituting the organic layer.

  There is no special restriction on the heat treatment method. The heat treatment temperature may be changed a plurality of times, and the heat history may be given by raising the temperature stepwise. The heat treatment apparatus is not particularly limited. For example, the heat treatment can be performed by a continuous heating apparatus such as an atmospheric pressure oven, an autoclave under pressure, a press machine, or a floating furnace. Examples of the heat treatment method include hot air injection, air floating, infrared radiation, microwave irradiation, and high frequency dielectric heating. At the stage of heat treatment, the volatile base (C) or acid (D) or ammonium carbonate (E) is volatilized or becomes a salt, leaving traces in the film, but affecting the performance of the film. Don't give.

(Flexible printed wiring board of the present invention)
Next, the flexible printed wiring board of the present invention will be described. That is, the flexible printed wiring board of the present invention is characterized by being covered with the moisture-proof coverlay film of the present invention.

  A preferred embodiment of such a flexible printed wiring board will be described with reference to the drawings.

  FIG. 2 is an enlarged schematic perspective view showing the vicinity of the tip of the flexible printed wiring board. The flexible printed wiring board shown in FIG. 2 includes an elongated flexible substrate main body (base material main body) 20 made of polyimide film, and a plurality of coatings formed on the surface portion of the substrate main body 20 by a printing method such as a screen printing method. The connection terminal 21 connected to the end of the wiring is provided. Moreover, the moisture-proof coverlay film 22 of the present invention is provided so as to cover and laminate the surface of the substrate body 20.

  The wiring is composed of a plurality of anode wirings 23 and a plurality of cathode wirings 24, and the connection terminal 21 is composed of a plurality of anode terminals 25 and a plurality of cathode terminals 26. In addition, the anode wiring 23 and the cathode wiring 24 are connected to the anode terminal 25 and the cathode terminal 26, respectively, at the distal end portion of the substrate body 20. The plurality of anode terminals 25 are arranged adjacent to each other and constitute an anode terminal group. The plurality of cathode terminals 26 are arranged adjacent to each other and constitute a cathode terminal group.

  As mentioned above, although one suitable embodiment of the flexible printed wiring board of the present invention was shown, the flexible printed wiring board of the present invention is not limited to such a thing.

  For example, in the present embodiment, a polyimide film is used as the substrate main body (base material main body) 7, but the substrate main body (base material main body) 7 is, for example, PET (polyethylene terephthalate), phenol in addition to the polyimide film. It can also be composed of resin, polyethylene naphthalate, or the like. Further, the wiring shown in FIG. 2 is for convenience, and such wiring is not limited to the wiring shown in FIG. 2 and can be various patterns of wiring.

  Although the flexible printed wiring board of the present invention has been described above, a preferred method for manufacturing the flexible printed wiring board of the present invention will be described below.

  The flexible printed wiring board of the present invention covers the flexible printed wiring board of the present invention by sandwiching the flexible printed wiring board between the two moistureproof covering lay films of the present invention and heating lamination. At least it can be manufactured. That is, a flexible printed wiring board that is closely coated with the two moisture-proof coverlay films of the present invention is manufactured by laminating the moisture-proof coverlay film of the present invention and a flexible wiring board on which a circuit is formed under heating. Can do.

  When manufacturing such a flexible printed wiring board of the present invention, it is preferable to use a moisture-proof coverlay film in which an adhesive layer is laminated on one surface of the moisture-proof coverlay film. Then, the surface of the adhesive layer of the moisture-proof coverlay film is tightly coated so that the flexible printed wiring board is sandwiched between two moisture-proof coverlay films of the present invention so that the surface of the adhesive layer faces the flexible printed wiring board. In this manner, the moisture-proof coverlay film / flexible printed wiring board / moisture-proof coverlay film are laminated in this order.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

  First, the evaluation method of the laminated film obtained by the preliminary test, the moisture-proof coverlay film obtained by each Example and each comparative example is demonstrated.

(I) Area ratio α of infrared absorption spectrum (method for measuring water content in film)
Regarding the moisture-proof coverlay film obtained in each example, the area ratio α [peak area S ₁ (3700 to 2500 cm ⁻¹ ) / peak area of the infrared absorption spectrum of the film using the ATR method among the above methods. was determined S ₂ (1800~1500cm ^-1)].

Here the peak area _S 1 (3700~2500cm ^-1) is a straight line connecting the absorbance two points absorbance and 2500 cm ^-1 in 3700 cm ^-1 as the baseline, was determined by area integration ranging 3700~2500cm ^-1. Also, the peak area _S 2 (1800~1500cm ^-1) is a connecting it straight two points absorbance absorbance and 1500 cm ^-1 in 1800 cm ^-1 as the baseline, was determined by area integration of a range of 1800～1500Cm ^-1 .

  In addition, for the measurement of the area ratio α, a specimen having an organic thin film surface exposed from the moisture-proof coverlay film obtained in each example is manufactured, and the ATR method is used for the organic thin film of the specimen. I went there. The specimen with such an organic thin film on the surface is placed in a glass bottle filled with a methylene chloride solution and its vapor in the moisture-proof coverlay film obtained in each example, and stored for one day at a temperature of 23 ° C. The organic thin film and the adhesive layer of the moisture-proof coverlay film were peeled off.

(Ii) Infrared absorption spectrum peak ratio β (measurement method of ionization degree)
Regarding the moisture-proof coverlay film obtained in each example, the peak ratio β [peak A ₁ (1560 cm ⁻¹ ) / from the ratio of the peak height of the absorbance of the infrared absorption spectrum of the film by the ATR method among the methods described above. Peak A ₂ (1700 cm ⁻¹ )] was determined.

Here, the absorbance of the peak A ₁ (1600cm ^-1), the straight line connecting two points of the absorbance and absorbance at 1500 cm ^-1 in 1600 cm ^-1 as the baseline, the height of the absorption maximum in the range of 1600～1500Cm ^-1 I asked for it. The peak _A 2 (1700 cm ^-1) was determined a straight line connecting two points of the absorbance and absorbance at 1600 cm ^-1 in 1800 cm ^-1 from the height of the absorption maximum in the range of the 1800～1600Cm ^-1 as the baseline.

  In addition, for the measurement of the peak ratio β, a specimen having an organic thin film surface exposed from the moisture-proof coverlay film obtained in each example is manufactured, and the ATR method is used for the organic thin film of the specimen. I went there. The specimen with such an organic thin film on the surface is placed in a glass bottle filled with a methylene chloride solution and its vapor in the moisture-proof coverlay film obtained in each example, and stored for one day at a temperature of 23 ° C. The organic thin film and the adhesive layer of the moisture-proof coverlay film were peeled off.

(Iii) Method for measuring water vapor transmission rate (WVTR) As an evaluation of the moisture resistance of the moisture-proof cover lay film obtained in each example and each comparative example, the measurement of water vapor transmission rate was conducted using JIS K7129-1992 plastic film and sheet. The test was performed according to the method B (infrared sensor method) of the water vapor permeability test method (instrument measurement method). Specifically, preliminary humidification was performed under conditions of a temperature of 60 ° C. and a relative humidity of 90%, and WVTR after 250 hours had elapsed from the start of humidification was measured at a temperature of 40 ° C. and a relative humidity of 90%. The measuring instrument was a relative humidity of 90% RH on the water vapor supply side, using the product name PERMA TRAN of a water vapor permeation tester manufactured by Modern Control. The measured value was expressed in the unit of g / m ² · day. The measurement limit value of WVTR by this method is 0.005 g / m ² · day, but considering the fluctuation of the measured value, all values below 0.02 g / m ² · day are 0.02 g / m or less. ² · day.

  Next, the evaluation method of the flexible printed wiring board obtained by coat | covering the moisture-proof cover-lay film obtained by each Example and the comparative example is demonstrated.

(Iv) Basicity of negative electrode terminal First, in an atmosphere having a relative humidity of 90% under a temperature condition of 60 ° C., a flexible printed wiring board obtained in each Example and each Comparative Example was applied with a voltage of 5 V and a current of 50 mA for 30 days. An accelerated environmental resistance test was conducted. Then, the basicity by the hydroxyl group derived from the electrolysis of the water vapor | steam permeate | transmitted by the negative electrode terminal side in the wiring of a flexible printed wiring board was measured using PH test paper.

(V) State of base film and the like After the environmental resistance acceleration test, the state of the flexible printed wiring board and the base film laminated thereon was measured.

(Vi) Measuring method of peeling of wiring The wiring of the flexible printed wiring board after the environmental resistance acceleration test was measured for peeling.

(Vii) Wiring short-circuit measuring method For the flexible printed wiring board after the accelerated environmental resistance test, an electroless plating used for wiring of the flexible printed wiring board was taken using a scanning electron microscope at a magnification of 5000 times. It was measured whether there was any fine needle-like metal crystal called whisker from the coating, and further, it was also measured whether there was a short circuit between the wires.

(Preliminary test) A laminated film in which an organic thin film was formed on a base film (polyimide film: product name Kapton EN, thickness 38 μm, manufactured by DuPont, USA) was prepared as a sample for measuring the Zn Auger electron spectrum of the organic thin film. The Zn Auger electron spectrum of the organic thin film was measured. In the measurement, first, an organic thin film was produced under the following conditions. In addition, it is also possible to peel another layer from the laminated film so as to expose the surface of the organic thin film, and to use this surface as a specimen of the organic thin film.

<Coating fluid>
Polyacrylic acid solid content concentration: 2.5 wt%, ZnO addition amount: 2.0 chemical equivalent, ammonia addition amount: 5.0 (mass ratio with respect to ZnO), ammonium carbonate addition amount: 5.5 (mass ratio with respect to ZnO) The coating liquid was prepared so that it might become. Specifically, trade names of polyacrylic acid (PAA) manufactured by Toagosei Co., Ltd. Aron A-10H: 200 g (2.74 mol), ZnO (manufactured by Wako Pure Chemical Industries): 55.7 g (2.74 mol) ), 28% ammonia aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.): 223 g (3.67 mol), ammonia carbonate (manufactured by Wako Pure Chemical Industries, Ltd.): 306 g (3.19 mol), to prepare a coating solution.

<Coating method>
Direct gravure method (gravure plate: 45 lines, depth: 800 μm, wet coating amount: about 22 g · m ² , multi-coater product name TM-MC / 5B manufactured by Hirano Techseed, base material: polyethylene terephthalate).

<Drying method>
In-line drying (drying oven setting: first zone 60 ° C. 15 m / sec, second zone 60 ° C. 15 m / sec, line speed: 4 m / min).

<Heat treatment>
The organic thin film was fixed to a ferro plate and heat-treated in a gear oven at 210 ° C. for 15 minutes. Next, the obtained organic thin film was subjected to chamfering with an inclination by a polishing method. Thereafter, the element distribution state of the organic thin film and the Auger electron spectrum of Zn at a point of 0.2 μm and a point of 0.4 μm from the surface side were measured. The measurement method was based on the following conditions.
Measuring device: Product name Quantera SXM manufactured by PHI
X-ray source: Al mono (1486.6 eV)
Detection area 20μmφ
Detection depth 4-5nm (take-off angle 45 °)
Measurement spectrum: Wide (0 to 1500 eV), narrow (490 to 505 eV corresponding to Zn-LMN Auger electrons).

  FIG. 3 shows a distribution state of elements confirmed by the measurement, and FIG. 4 shows a measurement result by an Auger electron spectrum analysis of Zn. In FIG. 4, ◇ indicates the relationship between the binding energy and strength of zinc by Auger electron spectrum analysis on the surface of the organic thin film, and □ indicates the zinc content by Auger electron spectrum analysis at a position 0.2 μm from the surface of the organic thin film. The relationship between the binding energy and the strength is shown, and Δ shows the relationship between the binding energy and the strength of zinc by Auger electron spectrum analysis at a position of 0.4 μm from the surface of the organic thin film. From the relationship between FIG. 3 and FIG. 4, it is estimated that the binding energy of Zn by Auger electron spectrum analysis has a peak at 496 to 498 eV, and this peak is mainly derived from the chemical bond between zinc and ammonia. It was.

The area ratio α of the infrared absorption spectrum of the organic thin film obtained as described above, the peak ratio β of the infrared absorption spectrum, the oxygen transmission rate and the water vapor transmission rate were measured as described above. 1.3, the peak ratio β was 8, and the water vapor permeability was 1 g / (m ² · day). From the measurement results of oxygen permeability and water vapor permeability, it was confirmed that the organic thin film produced as described above had excellent moisture resistance.

(Production Example 1 [Solution A])
Solution A for forming an organic thin film was produced as follows. As the polycarboxylic acid polymer (A), the trade name Aron A-10H (number average molecular weight 200,000, 25 wt% aqueous solution) of polyacrylic acid (PAA) manufactured by Toagosei Co., Ltd. was used. With respect to the PAA aqueous solution, ammonia water (a 28% by weight aqueous solution of reagent ammonia manufactured by Wako Pure Chemical Industries, Ltd.), zinc oxide (a reagent manufactured by Wako Pure Chemical Industries, Ltd.), and distilled water as volatile bases have the following composition. The solution A was obtained by sequentially adding and mixing with an ultrasonic homogenizer. A homogeneous transparent solution in which zinc oxide was completely dissolved by utilizing the complexing ability of zinc with a volatile base (ammonia).
Solution A composition PAA 25 wt% aqueous solution 250 g
210% 28% ammonia water
Zinc oxide 35g
505 g of distilled water
Total 1000g.

  In the composition of Solution A, ammonia was 400 mol% (4.0 chemical equivalents), 50 mol% (1.0 chemical equivalents) of zinc oxide, and PAA concentration was 6.25 wt% with respect to the carboxy group in PAA. .

(Production Example 2 [Flexible Printed Circuit Board])
A flexible printed wiring board (FPWB) was manufactured as follows. That is, after a plasma treatment is performed on one side of a 38 μm-thick polyimide film (base material (product name: Kapton EN manufactured by DuPont, USA)), a nickel chromium target (alloy of 90 mass% nickel and 10 mass% chromium) is used. Then, a nickel chromium vapor deposition layer having a thickness of about 6 nm is formed on the polyimide film using a conventional vacuum vapor deposition method, and copper (Cu) having a purity of 99.99% is further formed on the nickel chromium vapor deposition layer. A conductive metal layer was formed by vacuum deposition. Next, the conductive metal layer was etched to form a linear wiring pattern having a wiring width of 500 μm, a wiring interval of 300 μm, and a length of 50 mm. Thereafter, electroless tin (Sn) plating was applied to the wiring pattern to form a 1 μm thick tin plating layer, and a flexible printed wiring board (FPWB) was manufactured.

Example 1
Polyimide film (base film (thickness 38 μm)) / inorganic film (silicon oxide deposition film (thickness 0.025 μm)) / organic thin film (thickness 0.7 μm) / adhesive layer (thickness 1.5 μm) / organic Thin film (thickness 0.7 μm) / inorganic film (silicon oxide deposition film (thickness 0.025 μm)) / polyimide film (base film (thickness 38 μm)) / adhesive layer (thickness 25 μm) In addition, a moisture-proof coverlay film of the present invention was produced.

  That is, first, two polyimide films (product name Kapton EN, manufactured by DuPont, USA) are used as a base film, and a vacuum deposition method is used as a vapor deposition method, with a thickness of 0 on the surfaces of the two polyimide films. An inorganic film (silicon oxide vapor-deposited film) was formed so as to have a thickness of 0.025 μm, and two inorganic film-forming substrate films were obtained.

  Next, on the surface of the inorganic film of the two inorganic film-forming substrate films, the solution A obtained in Production Example 1 is applied to each bar coater (trade name K303PROFERR manufactured by RK PRINT-COAT IN STRAMENT). Then, heat treatment is performed in an oven at 200 ° C. for 60 minutes to obtain two organic / inorganic laminated films in which an inorganic layer and an organic thin film (thickness 0.7 μm) are laminated on a base material. It was.

  And after drying urethane type adhesives (the product name Dick Dry LX500 (main agent), KW75 (curing agent) made by Dainippon Ink Co., Ltd.) on the surface of the organic thin film of the one organic-inorganic laminated film. Coating is performed so that the thickness is 1.5 μm, and another organic / inorganic laminated film and the organic / inorganic laminated film after application of the urethane adhesive are laminated with the organic thin film surface interposed through an adhesive layer. The moisture-proof coverlay film of the present invention was obtained by pressure bonding using a thermal press roller maintained at 200 ° C.

  Next, an ethylene ethyl acrylate copolymer (ethyl acrylate content 8%) is melted and an ethylene ethyl acrylate copolymer is laminated on one substrate film surface of the moisture-proof coverlay film by an extrusion laminating method. A moisture-proof coverlay film of the present invention in which layers were further laminated was obtained. A moisture-proof coverlay film having such an adhesive layer may be referred to as a B stage coverlay film.

The area ratio α [peak area S ₁ (3700-2500 cm ⁻¹ ) / peak area S ₂ (1800-1500 cm ⁻¹ )] of the infrared absorption spectrum in the moisture-proof coverlay film thus obtained, the peak ratio β [Peak A ₁ (1560 cm ⁻¹ ) / Peak A ₂ (1700 cm ⁻¹ )] and water vapor transmission rate (WVTR) were measured by the methods described above. The obtained results are shown in Table 1.

  Next, using the two moisture-proof coverlay films thus obtained and the flexible printed wiring board (FPWB) obtained in Production Example 2, the surface of the adhesive layer of the moisture-proof coverlay film is The both sides of the FPWB were laminated so as to be on the FPWB side, and passed between thermal press rollers maintained at 200 ° C. to obtain the flexible printed wiring board of the present invention.

  Thus, about the flexible printed wiring board of this invention obtained, the basicity of a negative electrode terminal, the state of a base film, the peeling of wiring, and the short circuit of wiring were each measured as mentioned above. The results are as follows.

  In such basic measurement, it was confirmed that the PH value was 7, which was the same level as before energization. Moreover, in the measurement of the state of the base film and the like, the polyimide film used for the base film and the base of the flexible printed wiring board is not melted or pierced, and the shape of the pie fabric There was no unevenness. Furthermore, in the flexible printed wiring board of the present invention obtained in this way, no wiring peeling occurred. Moreover, in the flexible printed wiring board of the present invention thus obtained, whisker growth was suppressed and no short circuit of the wiring occurred.

(Example 2)
Polyimide film (base film (thickness 38 μm)) / inorganic film (silicon oxide deposition film (thickness 0.025 μm)) / organic thin film (thickness 0.7 μm) / adhesive layer (thickness 1.5 μm) / inorganic The moisture-proof coverlay film of the present invention laminated in the order of film (silicon oxide vapor deposition film (thickness: 0.025 μm)) / polyimide film (base film (thickness: 38 μm)) / adhesive layer (thickness: 25 μm) Manufactured.

  That is, first, two polyimide films (product name Kapton EN, manufactured by DuPont, USA) are used as a base film, and a vacuum deposition method is used as a vapor deposition method, with a thickness of 0 on the surfaces of the two polyimide films. An inorganic film (silicon oxide vapor-deposited film) was formed so as to have a thickness of 0.025 μm, and two inorganic film-forming substrate films were obtained.

  Next, the solution A obtained in Production Example 1 is applied to the surface of the inorganic film of the one inorganic film-forming base film using a bar coater (trade name K303PROFER manufactured by RK PRINT-COAT IN STRUMENT). After coating, heat treatment was performed in an oven at 200 ° C. for 60 minutes to obtain two organic / inorganic laminated films in which an inorganic layer and an organic thin film (thickness 0.7 μm) were laminated on a base material. And the thickness after drying a urethane type adhesive (a product name Dick Dry LX500 (main agent), KW75 (curing agent) made by Dainippon Ink Co., Ltd.) on the surface of the organic thin film of the organic-inorganic laminated film. The structure as described above, which is applied by using a thermal press roller which is coated at 1.5 μm and is maintained at 200 ° C. so that another inorganic film-forming substrate film is laminated via an adhesive layer. The moisture-proof coverlay film of this invention was obtained.

  Next, an ethylene ethyl acrylate copolymer (ethyl acrylate content 8%) is melted and an ethylene ethyl acrylate copolymer is laminated on one substrate film surface of the moisture-proof coverlay film by an extrusion laminating method. A moisture-proof coverlay film of the present invention in which layers were further laminated was obtained.

The area ratio α [peak area S ₁ (3700-2500 cm ⁻¹ ) / peak area S ₂ (1800-1500 cm ⁻¹ )] of the infrared absorption spectrum in the moisture-proof coverlay film thus obtained, the peak ratio β [Peak A ₁ (1560 cm ⁻¹ ) / Peak A ₂ (1700 cm ⁻¹ )] and water vapor transmission rate (WVTR) were measured by the methods described above. The obtained results are shown in Table 1.

  Next, using the two moisture-proof coverlay films thus obtained and the flexible printed wiring board (FPWB) obtained in Production Example 2, the surface of the adhesive layer of the moisture-proof coverlay film is The both sides of the FPWB were laminated so as to be on the FPWB side, and passed between thermal press rollers maintained at 200 ° C. to obtain the flexible printed wiring board of the present invention.

  With respect to the flexible printed wiring board thus obtained, the basicity of the negative electrode terminal, the state of the base film, the peeling of the wiring, and the short circuit of the wiring were measured as described above. The results are as follows.

  In such basic measurement, it was confirmed that the PH value was 7, which was the same level as before energization. In the measurement of the state of the base film and the like, the polyimide film used for the base film and the base of the flexible printed wiring board is not melted or perforated, and the pie dough-like unevenness Did not occur. Furthermore, in the flexible printed wiring board of the present invention obtained in this way, no wiring peeling occurred. Moreover, in the flexible printed wiring board of the present invention thus obtained, whisker growth was suppressed and no short circuit of the wiring occurred.

(Comparative Example 1)
A moisture-proof coverlay film as a comparison was laminated in the order of polyester terephthalate film (base film (thickness 50 μm)) / adhesive layer (thickness 70 μm).

  That is, a stretched polyethylene terephthalate film (PET film: product name Lumirror S10 manufactured by Toray, thickness 50 μm) is used as a base film, and an ethylene ethyl acrylate copolymer (ethyl acrylate content 8%) is formed on the base film. ) Was melted and laminated by an extrusion laminating method to obtain a moisture-proof coverlay film as a comparison in which an adhesive layer made of an ethylene ethyl acrylate copolymer was laminated on the base film surface.

  The water vapor transmission rate (WVTR) of the moisture-proof coverlay film thus obtained was measured by the method described above. The obtained results are shown in Table 1.

  Using the two moisture-proof coverlay films thus obtained and the flexible printed wiring board (FPWB) obtained in Production Example 2, both the surfaces of the adhesive layer of the moisture-proof coverlay film are on the FPWB side. Then, the two sides of the FPWB were laminated so as to be and passed between thermal press rollers maintained at 200 ° C. to obtain a flexible printed wiring board as a comparison.

  With respect to the flexible printed wiring board thus obtained, the basicity of the negative electrode terminal, the state of the base film, the peeling of the wiring, and the short circuit of the wiring were measured as described above. The results are as follows.

  In the measurement of the basicity of such a negative electrode terminal, the PH value was 12, which was more basic than before energization. In addition, the state of the base film and the like is such that the PET film used for the base film is melted, and further, the base film used for the wiring board is perforated, and the PET film has a pie fabric shape. The unevenness of was produced. Furthermore, when the peeling of the wiring was measured, it was confirmed that the peeling of the wiring occurred in part. Moreover, in the comparative flexible printed wiring board obtained in this way, the growth of whiskers has reached 1/4 or more of the distance between the wirings, and a short circuit between the wirings has also occurred.

(Comparative Example 2)
Moisture resistance as a comparison, laminated in the order of polyester terephthalate film (base film (thickness 50 μm)) / adhesive layer (thickness 1.5 μm) / polyester terephthalate film (base film (thickness 50 μm)) / adhesive layer A protective coverlay film was produced.

  That is, two stretched polyethylene terephthalate films (PET film: product name Lumirror S10 manufactured by Toray Industries Inc., thickness 50 μm) are used as a base film, and a urethane adhesive (Dainippon Ink Co., Ltd.) is used on the surface of one base film. The product name Dick Dry LX500 (main agent), KW75 (curing agent) mixture manufactured by the company was applied so that the thickness after drying was 1.5 μm, and another base material was applied to the base film. A laminated film was obtained by pressure bonding using a thermal press roller maintained at 200 ° C. so that the film was laminated through the adhesive layer. Thereafter, an ethylene ethyl acrylate copolymer (ethyl acrylate content 8%) is melted and an adhesive layer is formed by laminating the ethylene ethyl acrylate copolymer on the surface of one base film of the laminated film by an extrusion laminating method. Further, a moisture-proof cover lay film as a comparative laminate was obtained.

  The water vapor transmission rate (WVTR) of the moisture-proof coverlay film thus obtained was measured by the method described above. The obtained results are shown in Table 1.

  Next, using the two moisture-proof coverlay films thus obtained and the flexible printed wiring board (FPWB) obtained in Production Example 2, the surface of the adhesive layer of the moisture-proof coverlay film is The both sides of the FPWB were laminated so as to be on the FPWB side, and passed between thermal press rollers maintained at 200 ° C. to obtain a flexible printed wiring board for comparison.

  With respect to the flexible printed wiring board thus obtained, the basicity of the negative electrode terminal, the state of the base film, the peeling of the wiring, and the short circuit of the wiring were measured as described above. The results are as follows.

  In the measurement of the basicity of such a negative electrode terminal, the PH value was 12, which was more basic than before energization. In addition, the state of the base film and the like is such that the PET film used for the base film is melted, and further, the base film used for the wiring board is perforated, and the PET film has a pie fabric shape. The unevenness of was produced. Furthermore, when the peeling of the wiring was measured, it was confirmed that the peeling of the wiring occurred in part. Moreover, in the comparative flexible printed wiring board obtained in this way, the growth of whiskers has reached 1/4 or more of the distance between the wirings, and a short circuit between the wirings has also occurred.

  As is clear from the results shown in Table 1 and the measurement results of the basicity of the negative electrode terminal, the state of the base film, the peeling of the wiring, and the short circuit of the wiring, the moisture-proof coverlay film of the present invention is It was confirmed that the water vapor permeability was very low and the moisture resistance was high. Furthermore, it was confirmed that the flexible printed wiring board of the present invention can be used stably over a long period of time without any wiring peeling or short circuit.

  As described above, according to the present invention, a coverlay film having a very low water vapor permeability and capable of stably exhibiting a high level of moisture resistance over a long period of time, which covers a flexible printed wiring board Moisture-proof coverlay film capable of sufficiently preventing the negative terminal side on the wiring board from becoming basic due to water vapor, and peeling or short-circuiting of the wiring, and flexible printed wiring using the same A substrate can be provided.

  Therefore, since the moisture-proof coverlay film of the present invention is particularly excellent in moisture-proof properties, it is a moisture-proof coverlay film that is useful for applications that cover a flexible printed wiring board to protect a circuit.

It is a schematic diagram which shows one Embodiment of the apparatus for manufacturing a moisture-proof cover-lay film (IV). It is a schematic perspective view which expands and shows one Embodiment near the front-end | tip part of the flexible printed wiring board of this invention. It is a graph which shows the relationship between the distance from the surface of an organic thin film, and the composition distribution of the element in an organic thin film. It is a graph which shows the relationship between the binding energy of zinc by Auger electron spectrum analysis, and the intensity | strength positively correlated with the emitted amount of Auger electrons.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Feeding apparatus, 2 ... Inorganic film formation base film roll, 3 ... Inorganic film formation base film, 4 ... Corona discharge system, 5 ... Gravure roll, 6 ... Solution, 7 ... First drying furnace, 8 ... Laminate Device: 9 ... Heating roll, 10 ... Second drying furnace, 11 ... Accumula, 12 ... Winding device, 13 ... Moisture-proof coverlay film roll, 20 ... Substrate body, 21 ... Connection terminal, 22 ... Moisture-proof cover Ray film, 23 ... anode wiring, 24 ... cathode wiring, 25 ... anode terminal, 26 ... cathode terminal

Claims (11)

A moisture-proof cover lay film comprising a substrate film made of a polyimide film and a moisture-proof film laminated film laminated on one surface of the substrate film, the moisture-proof film laminated film,
An inorganic membrane;
It contains at least a polyvalent metal salt of the polycarboxylic acid polymer (A) and has an infrared absorption spectrum area ratio α [peak area S ₁ (3700 to 2500 cm ⁻¹ ) / peak area S ₂ (1800 to 1500 cm ⁻¹ )]. An organic thin film having an infrared absorption spectrum peak ratio β [Peak A ₁ (1560 cm ⁻¹ ) / Peak A ₂ (1700 cm ⁻¹ )] of 1.2 or more,
A moisture-proof coverlay film characterized by comprising:   The moisture-proof coverlay film according to claim 1, wherein the organic thin film is laminated on one surface of the base film through the inorganic film.   The moisture-proof coverlay film according to claim 1, wherein the inorganic film is laminated on one surface of the base film via the organic thin film.   The laminated film for moisture-proof film includes an organic layer formed by directly facing and adhering two organic thin films, and the inorganic film laminated on both surfaces of the organic layer. The moisture-proof coverlay film according to claim 1.   The moisture-proof film laminate film includes an organic layer formed by laminating two organic thin films via an adhesive layer, and the inorganic film laminated on both surfaces of the organic layer. The moisture-proof coverlay film according to claim 1.   The said polyvalent metal in the said organic thin film is at least 1 type of metal selected from the group which consists of zinc, a zirconium, copper, and nickel, The any one of Claims 1-5 characterized by the above-mentioned. Moisture-proof coverlay film.   The multivalent metal is zinc, and the binding energy according to Auger electron spectrum analysis of zinc has at least one peak between 496 and 498 eV. The moisture-proof coverlay film as described.   The moisture-proof coverlay film according to claim 1, wherein the inorganic film is an inorganic oxide vapor deposition film.   The moisture-proof coverlay film according to claim 8, wherein the inorganic oxide is a silicon oxide.   The moisture-proof coverlay film according to any one of claims 1 to 9, further comprising an adhesive layer laminated on the other surface of the base film.   A flexible printed wiring board, which is covered with the moisture-proof coverlay film according to any one of claims 1 to 10.

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