JP4690728B2 - Moisture-proof coverlay film and flexible printed wiring board using the same - Google Patents

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. For flexible printed wiring boards using a photosensitive dry film resist having a line insulation resistance of 1 × 10 13 Ω or more after humidity conditioning at% RH for 24 hours Light coverlay 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 cover lay film, the problem that the flexible printed wiring board was exposed to water by long-term use had arisen. 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 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 by the hydroxyl group generated by electrolysis and opening a hole, 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 circuit 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 low water vapor permeability and can stably exhibit a high level of moisture resistance over a long period of time. Moisture-proof coverlay film that can sufficiently prevent the negative terminal side on the wiring board from becoming basic and causing peeling or short-circuiting of the wiring board by water vapor when the printed wiring board is coated, and It aims at providing the used flexible printed wiring board.

  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 stacking an organic moisture-proof film, which has a higher molecular molecular structure density due to salt formation with functional groups and polyvalent metals, on the polyimide film, it has a low water vapor permeability and a high level of moisture resistance. It is a coverlay film that can be stably demonstrated over a wide area, and prevents the negative terminal side on the wiring board from becoming basic and peeling of the wiring due to water vapor when the flexible printed wiring board is covered The present inventors have found that a coverlay film that can be obtained is obtained, and have completed the present invention.

That is, the moisture-proof coverlay film of the present invention is a moisture-proof coverlay film comprising a base film made of a polyimide film and an organic moisture-proof film laminated on one surface of the base film, Moisture proof 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 S1 (3700 to 2500 cm ⁻¹ ) / peak area S2 (1800 to 1500 cm ⁻¹ )]. Is 2.5 or less, and the peak ratio β [peak A1 (1560 cm ⁻¹ ) / peak A2 (1700 cm ⁻¹ )] of the infrared absorption spectrum is 1.2 or more.
It is characterized by this. Here, a Kaiser (sometimes referred to as a wave number) is used as the unit of wavelength, and the unit symbol “ cm ⁻¹ ” is used, which is determined by the Kaiser = 1 / cm wavelength.

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

In addition, as the moisture-proof coverlay film of the present invention, another organic moisture-proof film is further laminated on one surface of the base film, and the two organic moisture-proof films are directly connected to each other. It is preferable that they are in close contact with each other.

Further, as the moisture-proof coverlay film of the present invention, another organic moisture-proof film is further laminated on one surface of the base film, and the two organic moisture-proof films are bonded to each other. it is preferably laminated through.

As the moisture-proof coverlay film of the present invention, the polyvalent metal contained as a constituent component in the polyvalent metal salt of the polycarboxylic acid polymer (A) in the organic moisture-proof film is zinc, zirconium, copper And at least one metal selected from the group consisting of nickel.

In the moisture-proof coverlay film of the present invention, the polyvalent metal contained in the polyvalent metal salt of the polycarboxylic acid polymer (A) in the organic moisture-proof film is zinc, and zinc It is preferable that the binding energy according to Auger electron spectrum analysis has at least one peak between 496 and 498 eV.

  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, a coverlay film having a low water vapor transmission rate and capable of stably exhibiting a high level of moisture resistance over a long period of time is provided on a wiring board when covered with a flexible printed wiring board. It becomes possible to provide a moisture-proof cover lay film that can suppress the negative terminal side of the substrate from becoming basic and causing peeling of the wiring, and a flexible printed wiring board using the moisture-proof cover lay film.

  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 comprising a base film made of a polyimide film and an organic moisture-proof film laminated on one surface of the base film, Organic moisture barrier
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 S1 (3700 to 2500 cm ⁻¹ ) / peak area S2 (1800 to 1500 cm ⁻¹ )]. Is 2.5 or less, and the peak ratio β [peak A1 (1560 cm ⁻¹ ) / peak A2 (1700 cm ⁻¹ )] of the infrared absorption spectrum is 1.2 or more. is there.

(Organic moisture barrier)
The organic moisture-proof film according to the present invention includes at least a polyvalent metal salt of the polycarboxylic acid-based polymer (A), and has an infrared absorption spectrum area ratio α [peak area S1 (3700 to 2500 cm ⁻¹ ) / peak area S2. (1800-1500 cm ⁻¹ )] is 2.5 or less, and the peak ratio β [peak A1 (1560 cm ⁻¹ ) / peak A2 (1700 cm ⁻¹ )] of the infrared absorption spectrum is 1.2 or more. It is an organic moisture-proof film having gas barrier properties and moisture-proof properties. 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 moisture-proof film according to the present invention satisfies the following specific requirements, the organic moisture-proof film is excellent in gas barrier properties such as oxygen even under high humidity. In addition, since it has long-term water resistance even in a natural environment such as a humid tropical region, it can be suitably used as a raw material for organic moisture-proof films.

  Here, the above-mentioned specific requirements are the drying conditions (temperature 30 ° C., relative humidity 0%) of the organic moisture-proof film formed solely from the polycarboxylic acid polymer (A) that is the raw material of the organic moisture-proof film according to the present invention. ) Means that the oxygen transmission coefficient is not more than a specific value. 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 moisture-proof film according to the present invention is not particularly limited as long as it is an existing polycarboxylic acid-based polymer, but the gas barrier property of the organic moisture-proof film according to the present invention. From the viewpoint of improving moisture resistance, 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) · It is preferable that it is below μm / ( m ² · day · MPa). Here, cubic cm is represented by a unit symbol “ cm ³ ”, and square m is represented by a unit symbol “ m ² ”. In addition, the standard state of temperature and pressure is represented by the symbol “STP”, which indicates a measured value at 23 ° C. and 1 atm. 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 moisture-proof film according to the present invention, an existing polycarboxylic acid polymer can be used, but an existing polycarboxylic acid polymer is a molecule. A generic 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 moisture-proof film according to the present invention is a copolymer of an α, β-monoethylenically unsaturated carboxylic acid and another ethylenically unsaturated monomer. From the viewpoint of improving the gas barrier property of the obtained organic moisture barrier film and the resistance to high-temperature steam and hot water, the copolymer composition is an α, β-monoethylenically unsaturated carboxylic acid monomer composition, Preferably it is 60 mol% or more, More preferably, it is 80 mol% or more, More preferably, it is 90 mol% or more, Most preferably, it is 100 mol%. Thus, as the polycarboxylic acid polymer (A) used as a raw material for the organic moisture-proof 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 from the viewpoint of the formation of the organic moisture-proof film, It is preferable that it is 000-1,000,000.

  In addition to the polycarboxylic acid polymer (A), other polymers can be used in the organic moisture-proof film according to the present invention as long as the gas barrier property and moisture-proof property of the organic moisture-proof film are not impaired. However, it is preferable to use only the polycarboxylic acid polymer (A) alone.

  Moreover, the polyvalent metal contained as a constituent in the polyvalent metal salt of the polycarboxylic acid polymer (A) contained in the organic moisture-proof film according to the present invention is a polyvalent metal having a metal ion valence of 2 or more. It is a single metal 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. Further, when a moisture-proof coverlay film is used for an electronic component equipped with a display device, the organic moisture-proof film is preferably transparent. Examples of the polyvalent metal contained in such an organic moisture-proof film include zinc or zirconium. Is mentioned. Furthermore, the organic moisture-proof film may be colored, and examples of the polyvalent metal contained in such an organic thin film include copper that is colored light green.

  Moreover, a polyvalent metal compound (B) is used as a raw material of the polyvalent metal salt contained in the organic moisture-proof 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 moisture barrier 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) is mixed or contained within a range that does not impair the gas barrier property and moisture proof property of the organic moisture-proof 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 property and moisture resistance of the organic moisture-proof film. It is. 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 moisture-proof film according to the present invention is not particularly limited. However, as described later, in the organic moisture-proof 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). ing.

  Therefore, when the polyvalent metal compound (B) that does not participate in carboxylate formation is present in the organic moisture-proof film according to the present invention, the polyvalent metal compound (B) is granular from the viewpoint of the transparency of the organic moisture-proof film. Thus, it is preferable that the particle size is smaller. 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.

  The organic moisture-proof film according to the present invention contains at least the polyvalent metal salt of the polycarboxylic acid polymer (A) as described above, measures a specific region of the infrared absorption spectrum, and has an area ratio α of 2. 5 or less, and the peak ratio β is 1.2 or more. The organic moisture-proof film according to the present invention having such characteristics is satisfactory in gas barrier properties such as oxygen and moisture-proof properties.

Next, the area ratio α [peak area S1 (3700 to 2500 cm ⁻¹ ) / peak area S2 (1800 to 1500 cm ⁻¹ )] of the infrared absorption spectrum of the organic moisture-proof 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 moisture-proof film. Although the state of moisture in the organic moisture-proof film is not clear, the moisture in the organic moisture-proof film according to the present invention refers to the state of being adsorbed in the organic moisture-proof 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 to 2500 cm ⁻¹ . Therefore, in the present invention, it was defined peak area of the infrared absorption spectrum of 3,700 to 2500 cm ^-1 peak area S1 and (3700~2500 cm ^-1). Peak area S1 (3700~2500 cm ^-1) is a straight line connecting two points of the absorbance and the absorbance of 2500 ^{cm -1} in 3700 ^{cm -1} as the baseline, be determined by area integration of a range of 3,700 to 2,500 cm ^-1 Can do.

Furthermore, C = O stretching vibration attributable to the polycarboxylic acid polymer (A) carboxyl groups in (-COOH) is an infrared wave number range of from 1800 to 1,600 cm ^-1, around 1700 ^{cm -1} Gives a peak with an absorption maximum. Further, C═O stretching vibration attributed to a salt of a carboxy group ( —COO ⁻ ) gives a peak having an absorption maximum in the vicinity of 1560 cm ^{−1 in} the infrared light wave number region of 1600 to 1500 cm ⁻¹ .

Such a peak attributed to a carboxyl group (—COOH) and a salt of a carboxyl group ( —COO ⁻ ) is a characteristic peak of the organic moisture-proof film according to the present invention. Here, the valence of the negative ion of the salt of the carboxy group = −1, which is represented by the symbol “ COO ⁻ ”. 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 moisture-proof film according to the present invention. In this invention, this area was prescribed | regulated as peak area S2 (1800-1500 cm < ^-1 >). Peak area S2 (1800~1500 cm ^-1) is a straight line connecting two points of the absorbance at 1800 ^{cm -1} absorbance and 1500 ^{cm -1} as the baseline is determined by the area integral of the range of 1800 to 1500 cm ^-1 be able to.

From the above, the ratio of the peak area S1 of the infrared absorption spectrum (3,700 to 2,500 cm ^-1) and infrared absorption spectrum of the peak area S2 (1800~1500 cm ^-1), i.e., the peak area S1 (3,700 to 2,500 cm ^-1 ) / Peak area S2 (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 moisture-proof 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 peak area S1 and the peak area S2 are calculated, and the ratio between the two is obtained. As a typical measurement condition example, a laminate in which the organic moisture-proof film according to the present invention is formed on a base material is used as a sample, by the ATR method, and as the ATR prism, KRS-5 (Thallium Bromide-Ioide) is used. , 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 A1 (1560 cm ⁻¹ ) / peak A2 (1700 cm ⁻¹ )] of the infrared absorption spectrum of the organic moisture barrier film is the polycarboxylic acid polymer (A) in the organic moisture barrier film. And an index representing the degree of metal salt formation between the polyvalent metal compound (B). The peak A1 (1560 cm ⁻¹ ) constituting the peak ratio β of the infrared absorption spectrum is the absorption of the infrared absorption spectrum of C═O stretching vibration around 1560 cm ⁻¹ attributed to the carboxyl group salt ( —COO ⁻ ). Peak area or peak height. That is, the C═O stretching vibration usually attributed to a carboxylate ( —COO ⁻ ) gives an absorption peak having an absorption maximum in the vicinity of 1560 cm ^{−1 in} the infrared light wave number region of 1600 to 1500 cm ⁻¹ . Peak A1 (1560 ^{cm -1)} is a straight line connecting two points of the absorbance at 1600 ^{cm -1} absorbance and 1500 ^{cm -1} as the baseline, the peak area from the area integration in the range of 1600 to 1500 cm ^-1, 1600 The peak height can be determined from the height of the absorption maximum in the range of ˜1500 cm ⁻¹ .

The peak A2 (1700 cm ⁻¹ ) constituting the peak ratio β is an infrared absorption peak that is separated and independent from the peak A1 (1560 cm ⁻¹ ), and is 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 A2 (1700 ^{cm -1)} is, 1800 ^cm absorbance and 1600 ^cm peak area a straight line connecting two points from the area integral of the range as a base line 1 800 to 1600 cm ^-1 absorbance ^{-1 -1,} The peak height can be determined from the height of the absorption maximum in the range of 1800 to 1600 cm ⁻¹ . The absorbance of the organic moisture barrier film is proportional to the amount of chemical species having infrared activity present in the organic moisture barrier film. Therefore, the ratio of the peak of the infrared absorption spectrum, that is, the peak A1 (1560 cm ⁻¹ ) / peak A2 (1700 cm ⁻¹ ) is defined as the peak ratio β of the infrared absorption spectrum, and the polyvalent metal in the organic moisture-proof film And a carboxy group salt forming a salt ( —COO ⁻ ) and a free carboxy group (—COOH) can be used as a scale for expressing the ratio.

The peak ratio β of the infrared absorption spectrum of the organic moisture-proof film according to the present invention is 1.2 or more and 10,000 or less. From the viewpoint of the moisture-proof property of the organic moisture-proof film, the peak ratio β is 2.0 or more and 10,000 or less. Is preferably 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 A1 (1560 cm ⁻¹ ) using the infrared absorption of C═O stretching vibration around 1560 cm ⁻¹ attributed to the salt of the carboxy group ( —COO ⁻ ), the peak ratio β Is an upper limit of 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 A1 (1560 cm ⁻¹ ) is small.

Furthermore, when the organic moisture-proof 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 ^The C = O stretching vibration attributed to- ) gives an absorption peak having an absorption maximum in the vicinity of 1560 cm ^{-1 in} the infrared light wave number region of 1600 to 1500 cm ^-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. Even in such a case, as described above, the peak ratio β [peak A1 (1560 cm ⁻¹ ) / peak A2 (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 moisture-proof 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 both absorption spectra is measured, and the ratio between the two is obtained.

As a typical measurement condition example, a sample exposing the organic moisture-proof film of the present invention is used, and the total reflection infrared analysis method (also referred to as ATR method) is used. As the ATR prism, KRS-5 (Thallium Bromide-Ioide) is used. Use, measurement at an incident angle of 45 degrees, a resolution of 4 cm ⁻¹ , and an integration count of 30 times 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 moisture-proof film | membrane concerning this invention, it is preferable that the said polyvalent metal is zinc and it has at least one peak between 496-498eV in the binding energy by the Auger electron spectrum analysis of zinc.

  Thus, more suitable conditions for the organic moisture-proof film according to the present 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 moisture-proof film according to the present invention, when Auger electron spectrum analysis is performed, the L inner-shell electrons of zinc are ionized by irradiated X-rays, and vacancies are formed in the L-shell. As a result, the M shell electron in the upper orbital transitions to the L shell, and when induced, the N shell electron in the upper orbital further transitions to the M shell. The inventor of the present invention has a positive correlation between the magnitude of Auger electron emission in the Zn-LMN transition process corresponding to the process of such electron transition and the moisture-proof property of the organic moisture-proof film. I found it. 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 has a positive correlation with the moisture-proof property of the organic moisture-proof 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 moisture-proof film according to the present invention is excellent in gas barrier properties such as water vapor and oxygen even under high humidity.

Further, the organic moisture-proof film according to the present invention is characterized in that it is excellent in moisture resistance as well as gas barrier properties such as oxygen. That is, moisture resistance and the organic moisture-proof film referred to in the present invention, the temperature 40 ° C., in an atmosphere of 90% RH, a water vapor permeability of 100g / ^(m 2 · day) or less, ^2-preferably 60 g / ^(m day) or less (90% relative humidity on the water vapor supply side). Here, the square m is represented by the unit symbol “ m ² ”.

The density of the organic moisture-proof film in 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 . Here, cubic cm is represented by a unit symbol “ cm ³ ”. When an organic moisture-proof 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 resistance tends to be not obtained. On the other hand, an organic moisture-proof film having a density exceeding 2.89 g / cm ³ increases the amount of polyvalent metal compound used, and makes it difficult to form an organic moisture-proof film after coating. The density of such an organic moisture-proof film can be measured according to JIS K7112 (method for measuring the density and specific gravity of plastic).

  In the organic moisture-proof film according to the present invention, the thickness of one organic moisture-proof film is not particularly limited, but from the viewpoint of handling properties of the moisture-proof cover lay film, the thickness of one organic moisture-proof film is 0.001 μm to It is preferably 200 μm, more preferably 0.01 μm to 100 μm, and particularly preferably 0.1 μm to 10 μm. In such an organic moisture-proof film, when the thickness of one organic moisture-proof film is less than 0.001 μm, it becomes difficult to form the organic moisture-proof film, and stable production tends to be impossible. On the other hand, when the thickness of the organic moisture-proof film exceeds 200 μm, coating is difficult, and there is a tendency to cause a problem in manufacturing.

The organic moisture barrier film according to the present invention has a water vapor permeability of 0.02 g / ( m ² · day) at 40 ° C. and 90% relative humidity after standing for 250 hours under pre-humidification conditions at 60 ° C. and 90% relative humidity. It is preferable that the following is maintained.

  Further, the organic moisture-proof film according to the present invention is formed by laminating two organic moisture-proof films directly facing each other and adhering to each other, and laminated on both sides of the organic layer, or 2 It can be suitably used that the organic thin film is formed by laminating the organic thin films through an adhesive layer.

  Such a moisture-proof coverlay film is formed by laminating two organic moisture-proof films directly or via an adhesive layer. Therefore, even when a micro pinhole is formed in the film thickness direction of one organic moisture barrier film, another organic moisture barrier film is further laminated to prevent the micro pin hole from being connected. Property and moisture resistance can be maintained.

  The thickness of the adhesive layer is not particularly limited, but is preferably 0.1 to 100 μm, and preferably 0.5 to 10 μm, from the viewpoint of preventing deterioration of gas barrier properties and moisture resistance obtained. More preferred. If the thickness of the adhesive layer is less than 0.1 μm, the adhesion of the organic moisture-proof film tends to be difficult. On the other hand, if it exceeds 100 μm, the coating tends to be difficult and causes problems in production.

(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 includes the organic moisture-proof 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 cover lay film of the present invention, the moisture-proof cover lay film (A) in which the organic moisture-proof film is laminated on one surface of the base film, and the one surface of the base film. Moisture-proof coverlay film (b) formed by laminating two organic moisture-proof films through an adhesive layer, and two organic moisture-proof films directly on one surface of the base film A moisture-proof coverlay film (c) formed by opposing and closely contacting each other is preferable.

  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 140 ° C are preferred, and adhesives having a temperature of from 50 ° C to 98 ° C 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 organic moisture barrier film will be described. 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 formed organic moisture barrier film. 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 solution), 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 moisture-proof 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 viewpoint of moldability and transparency of the organic moisture-proof film. In addition, from the viewpoint of setting the peak ratio β of the infrared absorption spectrum of the obtained organic moisture-proof film to 1.2 or more (preferably 2.0 or more, more preferably 4.0 or more), a polycarboxylic acid polymer is used. It is preferable that the compounding quantity of the polyvalent metal compound (B) with respect to the quantity of (A) is 0.5 to 10 chemical equivalents with respect to all the carboxy groups in the polycarboxylic acid 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). On the other hand, when the addition amount exceeds 60 chemical equivalents, there is a problem in film production (film formation). In the case of using a zinc compound as the polyvalent metal compound, from the viewpoint of producing an organic 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. It is preferable to mix 2 to 120 mol of the volatile base (C) with respect to 1 mol of the zinc compound, and particularly when the volatile base (C) is ammonia, 4 to 60 mol with respect to 1 mol of the zinc compound. It is preferable to mix them in moles.

  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 (B) will be described.

[Method for producing moisture-proof coverlay film (b)]
The manufacturing method of the moisture-proof coverlay film (b) includes (1) a step of obtaining two films in which an organic moisture-proof film is formed on the surface of the base film, and (2) two organic moisture-proof films formed as an adhesive layer. It is a manufacturing method including the process (The process of obtaining a moisture-proof cover-lay film (b)) laminated | stacked through this.

  (1) In the step of obtaining two films in which an organic moisture-proof film is formed on the surface of a base film, and the step of obtaining two organic moisture-proof films, the solution or dispersion ( An organic moisture-proof film (organic moisture-proof film laminate) is obtained by applying and drying a coating solution.

  As a method for coating the coating liquid on the substrate film, a known coating method can be used without particular limitation, and it is performed by dipping or spraying, and using 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 a state (wet) immediately after coating the solution or dispersion on the substrate film is preferably 0.02 μm to 1 mm, and 0.5 μm. More preferably, it is -500 micrometers. 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 and the instantaneous multiphotometry system MCPD-2000 is used.

  In the present invention, the viscosity of the solution or dispersion in a state immediately before the solution or dispersion is applied onto the substrate film can be adjusted as appropriate.

  The method of evaporating and drying the solvent after applying the coating liquid on the surface of the substrate 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 composed of the polycarboxylic acid polymer (A), the polyvalent metal compound (B), the volatile base (C) or the acid (D) on the base film, the polyvalent metal compound (B) is not yet present. It exists as a reaction molecule, a polyvalent metal salt with the polycarboxylic acid polymer (A), and a metal complex salt with the 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. Thus, the said solution or dispersion liquid is apply | coated on a base film, and it dries and forms an organic moisture-proof film | membrane.

  And the organic moisture-proof film laminated | stacked on the surface of a base 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, An organic moisture-proof film can be formed on the surface. 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 moisture-proof film in the obtained organic moisture-proof film laminate 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). 0.0), heat treatment is preferably performed 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 not to be 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 moisture-proof 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.

(2) Step of laminating two organic moisture-proof films through an adhesive layer In step (2), the organic moisture-proof film surfaces of the two organic moisture-proof film laminates obtained as described above are bonded together. A moisture-proof coverlay film (B) is obtained by laminating through the agent layer.

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

  In addition, the method of applying the adhesive to the organic moisture-proof film surface is not particularly limited, and a known coating method can be used, and dipping, spraying, coater, printing machine, or brush can be used. Can be used. 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 surfaces of the two organic moisture-proof films, and only on one surface of the two organic moisture-proof films. An adhesive may be applied. Furthermore, it is preferable that the coating thickness when the adhesive is applied to the organic moisture-proof film is sufficient to realize a suitable thickness of the above-described adhesive layer.

  Further, the method for adhering the organic moisture-proof film surfaces is not particularly limited, and a known method can be used as appropriate, and a dry lamination method, an extrusion lamination method, a hot melt lamination method, or the like can be used. It is.

  Thus, the moisture-proof property of this invention laminated | stacked in order of base film / organic moisture-proof film / adhesive layer / organic moisture-proof film / base film by laminating | stacking organic moisture-proof film surfaces through an adhesion layer in this way. A coverlay film (b) can be obtained.

  Next, an embodiment of an apparatus for producing a moisture-proof coverlay film (b) suitable for carrying out the steps (1) and (2) for producing the moisture-proof coverlay film (b) 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 (B).

  The manufacturing apparatus shown in FIG. 1 includes a feeding device 1, and a base film roll 2 in which the base film 3 described in the manufacturing process (1) is wound is installed in the feeding device 1. Has been.

  Moreover, the manufacturing apparatus shown in FIG. 1 includes a corona discharge system 4 and a gravure roll 5 in a direction in which the base film 3 fed from the feeding apparatus 1 travels. It is in contact with 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. Furthermore, the manufacturing apparatus shown in FIG. 1 includes a first drying furnace 7 in the direction in which the 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.

  In addition, the manufacturing apparatus shown in FIG. 1 includes an organic moisture-proof film laminate that has passed through the first drying furnace 7 and an organic moisture-proof film laminate that has been applied with an adhesive after passing through the laminate device 8 (hereinafter referred to as “adhesion layer formation”). A heating roll 9, a second drying furnace 10, an accumulator 11, and a winding device 12 are provided in the traveling direction of the “organic moisture-proof film laminate”.

  When producing an organic moisture-proof film laminate using such a production apparatus shown in FIG. 1, first, as a step of obtaining an organic moisture-proof film laminate, a base film roll 2 is set in the feeding device 1, The base film 3 is fed out. The surface of the fed film 3 passes through the corona discharge system 4 and is subjected to corona discharge treatment. The 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 subjected to the discharge treatment. In addition, since the surface of the base film 3 is subjected to the corona discharge treatment as described above, it is easy to apply the solution 6 uniformly. Then, the base film 3 coated with the solution 6 is guided to the first drying furnace 7 and subjected to heat treatment. Such an operation is performed simultaneously on two lines, and two organic moisture-proof film laminates are obtained.

  Next, in the present embodiment, a process for obtaining a moisture-proof coverlay film (B) will be described. First, of the two organic moisture-proof film laminates obtained as described above, an adhesive is applied to the organic moisture-proof film surface of one organic moisture-proof film laminate using the laminating device 8 to form an adhesive layer. An organic moisture-proof film laminate is obtained. Thereafter, the organic moisture-proof film surface of the other organic moisture-proof film laminate and the adhesive layer surface of the adhesive layer-forming organic moisture-proof film laminate are pressure-bonded using a heating roll 9. By performing such pressure bonding, it is possible to obtain a moisture-proof coverlay film (b) laminated in the order of base film / organic moisture-proof film / adhesive layer / organic moisture-proof film / base film. Then, the moisture-proof coverlay film (B) that has been pressure-bonded by the heating roll 9 is guided to the second drying furnace 10 and subjected to heat treatment. In addition, between the 1st drying furnace 7 and the heating roll 9, as needed, surface treatment of the organic moisture-proof film surface of an organic moisture-proof film laminated body by corona discharge or atmospheric pressure plasma (in order to raise the effect of pressure bonding ( (Not shown). Further, the moisture-proof coverlay film (b) 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 (b) can be obtained.

  As mentioned above, although suitable embodiment of the apparatus for manufacturing a moisture-proof cover-lay film (b) was described, the apparatus or method for manufacturing a moisture-proof cover-lay film (b) is limited to the said embodiment. It is not a thing.

[Method for Producing Moisture-proof Coverlay Film (I)]
The method for producing the moisture-proof coverlay film (I) is a production method including a step of forming an organic moisture-proof film on the surface of the base film 3 (a step of obtaining the moisture-proof coverlay film (I)).

[Method for producing moisture-proof coverlay film (b)]
The manufacturing method of the moisture-proof coverlay film (b) includes (1a) a step of forming an organic moisture-proof film on the surface of the substrate film (a step of obtaining an organic moisture-proof film laminate), and (2a) on the surface of the substrate film. (A step of obtaining an adhesive layer-forming organic moisture-proof film laminate), (3a) a manufacturing method comprising a step of extruding and laminating an adhesive layer on one surface of the adhesive layer-forming organic moisture-proof film laminate is there. In this way, a moisture-proof coverlay film (b) laminated in the order of base film / organic moisture-proof film / adhesive layer / organic moisture-proof film / base film / adhesive layer can be obtained.

  In addition, when the organic moisture-proof film surfaces of the two organic moisture-proof film laminates 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 The pressure bonding is preferably performed at a pressure of 1 × 10 6 MPa, and more preferably performed at a pressure of 1 KPa to 1 MPa under a temperature condition of 100 to 300 ° C.

  And the obtained moisture-proof cover-lay film (b) is heat-treated at a temperature in the range of 60 to 400 ° C, preferably 100 to 300 ° C, more preferably 150 to 250 ° C. 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 moisture-proof film in the obtained moisture-proof cover lay film (b) has an area ratio α of the infrared absorption spectrum of 2.5 or less (preferably 0.01 to 2.3, more preferably 0.8). From the viewpoint of setting to 01 to 2.0), 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 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 S1 (3700 to 2500 cm ⁻¹ ) / peak area of the infrared absorption spectrum of the film using the ATR method among the above methods. S2 (1800-1500 cm < ^-1 >)] was calculated | required.

Here the peak area S1 (3700~2500 cm ^-1) is a straight line connecting the absorbance two points 3700 ^{cm -1} absorbance and 2500 ^{cm -1} as a baseline, the area integration in the range of 3,700 to 2500 cm ^-1 Asked. The peak area S2 (1800~1500 cm ^-1) is, 1800 ^{cm -1} of the straight line connecting two points of the absorbance of absorbance and 1500 ^{cm -1} as a baseline, the area integral of the range of 1,800 to 1500 cm ^-1 Determined by

  In addition, the measurement of the area ratio α is performed by manufacturing a specimen in which the surface of the organic moisture-proof film is exposed from the moisture-proof cover lay film obtained in each example, and using the ATR method for the organic moisture-proof film of the specimen. It was performed by using. A specimen having such an organic moisture-proof film on the surface is placed in a glass bottle filled with a methylene chloride solution and its vapor in the moisture-proof cover lay film obtained in each example and stored for one day at a temperature of 23 ° C. The moisture-proof coverlay film was manufactured by peeling off the organic moisture-proof film and the adhesive layer.

(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 A1 (1560 cm ⁻¹ ) / from the ratio of the peak height of the infrared absorption spectrum of the film by the ATR method among the methods described above. Peak A2 (1700 cm ⁻¹ )] was determined.

Here, the absorbance of the peak A1 (1600 ^{cm -1),} a straight line connecting two points of the absorbance at 1600 ^{cm -1} absorbance and 1500 ^{cm -1} as a baseline, the absorption maximum in the range of 1,600-1,500 cm ^-1 From the height of. The peak A2 (1700 ^{cm -1)} is, 1800 ^cm absorbance and 1600 height of the absorption maximum in the range of ^cm a straight line connecting two points of the absorbance of ^-1 as a baseline 1 800 to 1600 cm ^{-1 -1} I asked for it.

  In addition, the peak ratio β is measured by manufacturing a specimen having an organic moisture-proof film surface on the surface from the moisture-proof coverlay film obtained in each example, and using the ATR method for the organic moisture-proof film of the specimen. It was performed by using. A specimen having such an organic moisture-proof film on the surface is placed in a glass bottle filled with a methylene chloride solution and its vapor in the moisture-proof cover lay film obtained in each example and stored for one day at a temperature of 23 ° C. The moisture-proof coverlay film was manufactured by peeling off the organic moisture-proof film and the adhesive layer.

(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 limit of the measured 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 ² or less. It was described as m 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.

(Preliminary test) Measurement of Zn Auger electron spectrum of organic moisture-proof film A laminated film in which an organic moisture-proof film is formed on a base film (polyimide film: product name Kapton EN, thickness 38 μm, manufactured by DuPont, USA) as a sample The Zn Auger electron spectrum of the organic moisture barrier film was measured. In the measurement, first, an organic moisture-proof 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 moisture-proof film, and to use this surface as a specimen of the organic moisture-proof 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 moisture-proof film was fixed to a ferro plate and heat-treated in a gear oven at 210 ° C. for 15 minutes.

Next, the obtained organic moisture-proof film was subjected to chamfering with an inclination by a polishing method. Thereafter, the state of element distribution of the organic moisture-proof 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).

The distribution state in the thickness direction of the element confirmed by the measurement is shown in FIG. The unit of thickness is μm ( micrometer ). Moreover, the measurement result by the Auger electron spectrum analysis of Zn confirmed by the measurement is shown in FIG. 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 moisture-proof film obtained as described above, the peak ratio β of the infrared absorption spectrum, the oxygen permeability and the water vapor permeability were measured as described above. Was 1.3, the peak ratio β was 8, and the water vapor permeability was 1 g / ( m ² · day). From the measurement results of such oxygen permeability and water vapor permeability, it was confirmed that the organic moisture barrier film produced as described above has excellent moisture resistance.

(Production Example 1 [Solution A])
Solution A for forming an organic moisture barrier 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).
Composition of solution A 250 g 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 by 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
The moisture-proof cover-lay film of the present invention was produced by laminating polyimide film (base film (thickness 38 μm)) / organic moisture-proof film (thickness 0.7 μm) in this order.

  On the surface of the two polyimide films, the solution A obtained in Production Example 1 was applied using a bar coater (trade name K303PROFERR, manufactured by RK PRINT-COAT IN STRUMENT), and then in an oven. Two organic moisture-proof film laminates obtained by heat-treating at 200 ° C. for 60 minutes and having a base film and an organic moisture-proof film (thickness 0.7 μm) laminated thereon were obtained.

  Then, a urethane-based adhesive (a product name Dick Dry LX500 (main agent), KW75 (curing agent) mixture manufactured by Dainippon Ink Co., Ltd.) is dried on the surface of the organic moisture-proof film of the organic moisture-proof film laminate. The film is coated so that the thickness after that becomes 1.5 μm, and the organic moisture-proof film laminate is bonded to another organic moisture-proof film laminate and the organic moisture-proof film laminate after applying the urethane adhesive. The moisture-proof coverlay film of the present invention was obtained by pressure bonding using a thermal press roller maintained at 200 ° C. so as to be laminated through the layers.

  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 S1 (3700 to 2500 cm ⁻¹ ) / peak area S2 (1800 to 1500 cm ⁻¹ )] of the infrared absorption spectrum in the moisture-proof coverlay film thus obtained, the peak ratio β [Peak A1 (1560 cm ⁻¹ ) / Peak A2 (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, etc., and peeling of wiring were measured as mentioned above, respectively. 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 or the like, neither the base film nor the polyimide film used for the base of the flexible printed wiring board was melted or perforated. Furthermore, in the flexible printed wiring board of the present invention obtained in this way, no wiring peeling occurred.

(Example 2)
Polyimide film (base film (thickness 38 μm)) / organic moisture barrier film (thickness 0.7 μm) / adhesive layer (thickness 1.5 μm) / organic moisture barrier film (thickness 0.7 μm) / polyimide film (base material) A moisture-proof cover lay film of the present invention was produced in the order of film (thickness 38 μm) / adhesive layer (thickness 25 μm).

That is, first, had use two sheets of polyimide film (DuPont Co. Product name Kapton EN) as a substrate film.

Then, before the front surface on Kimoto material film, a bar coater (RK solution A obtained in Production Example 1
Application using PRINT-COAT IN STRUMENT (trade name K303PROFERR), and then heat-treating in an oven at 200 ° C. for 60 minutes to form an organic moisture-proof film (thickness 0.7 μm) on the base film Two organic moisture-proof film laminates were stacked. And the thickness after drying a urethane type adhesive (the product name Dick Dry LX500 (main agent), KW75 (curing agent) made by Dainippon Ink) on the surface of the organic moisture-proof film of the organic moisture-proof film laminate. Was applied by using a thermal press roller that was kept at 200 ° C. so that another organic moisture-proof film laminate was laminated via an adhesive layer. A moisture-proof coverlay film of the present invention having a simple structure was obtained.

  Then, an ethylene ethyl acrylate copolymer (ethyl acrylate content 8%) is melted and an ethylene ethyl acrylate copolymer is laminated on one base film surface of the moisture-proof coverlay film by an extrusion laminating method. An inventive moisture-proof coverlay film was obtained.

The area ratio α [peak area S1 (3700 to 2500 cm ⁻¹ ) / peak area S2 (1800 to 1500 cm ⁻¹ )] of the infrared absorption spectrum in the moisture-proof coverlay film thus obtained, the peak ratio β [Peak A1 (1560 cm ⁻¹ ) / Peak A2 (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 cover lay 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 cover lay 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 cover lay film are on the FPWB side. The FPWB was laminated so that both sides were sandwiched and passed between thermal press rollers maintained at 200 ° C. to obtain a flexible printed wiring board for comparison.

  The flexible printed wiring board thus obtained was measured for the basicity of the negative electrode terminal, the state of the base film, etc. and the peeling of the wiring 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. Further, the state of the base film and the like was such that the PET film used for the base film was melted, and further, the base material used for the wiring board was perforated. Furthermore, when the peeling of the wiring was measured, it was confirmed that the peeling of the wiring occurred in part.

(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 ethylene ethyl acrylate copolymer is laminated on the surface of one of the base films of the laminated film by an extrusion laminating method. A comparative moisture-proof coverlay film 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.

  The flexible printed wiring board thus obtained was measured as described above for the basicity of the negative electrode terminal, the state of the base film, and the peeling of the wiring. 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. Further, the state of the base film and the like was such that the PET film used for the base film was melted, and further, the base material used for the wiring board was perforated. Furthermore, when the peeling of the wiring was measured, it was confirmed that the peeling of the wiring occurred in part.

  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, etc., and the peeling of the wiring, the moisture-proof coverlay film of the present invention has a water vapor permeability. It was confirmed to have a low and high moisture resistance. Furthermore, it was confirmed that the flexible printed wiring board of the present invention can be used stably for a long period of time without peeling of the wiring.

  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 A moisture-proof coverlay film capable of preventing the negative terminal side on the wiring board from becoming basic due to water vapor and peeling of the wiring, and a flexible printed wiring board using the same are provided. It becomes possible.

  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 (b). 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 moisture-proof film, and the composition distribution of the element in an organic moisture-proof 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 ... Base film roll, 3 ... Base film, 4 ... Corona discharge system, 5 ... Gravure roll, 6 ... Solution, 7 ... First drying furnace, 8 ... Laminating apparatus, 9 ... Heating roll DESCRIPTION OF SYMBOLS 10 ... 2nd drying furnace, 11 ... Accumulation, 12 ... Winding device, 13 ... Moisture-proof coverlay film roll, 20 ... Substrate body, 21 ... Connection terminal, 22 ... Moisture-proof coverlay film, 23 ... Anode Wiring 24 ... Cathode wiring 25 ... Anode terminal 26 ... Cathode terminal

Claims (7)

A moisture-proof coverlay film comprising a base film made of a polyimide film and an organic moisture-proof film laminated on one surface of the base film, wherein the organic moisture-proof film is
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 S1 (3700 to 2500 cm ⁻¹ ) / peak area S2 (1800 to 1500 cm ⁻¹ )]. Is 2.5 or less, and the peak ratio β [peak A1 (1560 cm ⁻¹ ) / peak A2 (1700 cm ⁻¹ )] of the infrared absorption spectrum is 1.2 or more.
A moisture-proof coverlay film.   The other organic moisture barrier film is further laminated on one surface of the base film, and the two organic moisture barrier films are directly opposed to each other and are in close contact with each other. 2. A moisture-proof cover lay film according to 1.   2. The organic vapor barrier film of another sheet is further laminated on one surface of the base film, and the two organic vapor barrier films are laminated through an adhesive layer. The moisture-proof coverlay film as described in 1.   The polyvalent metal contained as a constituent in the polyvalent metal salt of the polycarboxylic acid polymer (A) in the organic moisture-proof film is at least one selected from the group consisting of zinc, zirconium, copper and nickel. The moisture-proof coverlay film according to any one of claims 1 to 3, wherein the moisture-proof coverlay film is a metal.   The polyvalent metal contained in the polyvalent metal salt of the polycarboxylic acid polymer (A) in the organic moisture-proof film is zinc, and the binding energy of zinc by Auger electron spectrum analysis is 496 to 498 eV. The moisture-proof coverlay film according to any one of claims 1 to 4, wherein the moisture-proof coverlay film has at least one peak.   The moisture-proof coverlay film according to any one of claims 1 to 5, 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 6.

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