WO2015087884A1

WO2015087884A1 - Mold-release polyimide film, laminated board having mold-release polyimide film having adhesive layer, laminated board, monolayer or multilayer wiring board having mold-release polyimide film having adhesive layer, and method for manufacturing multilayer wiring board

Info

Publication number: WO2015087884A1
Application number: PCT/JP2014/082587
Authority: WO
Inventors: 薫平山田; 藤本　大輔; 哲郎岩倉; 陽一金子; 村井　曜
Original assignee: 日立化成株式会社
Priority date: 2013-12-09
Filing date: 2014-12-09
Publication date: 2015-06-18
Also published as: JP6561841B2; KR20160094972A; JPWO2015087884A1; KR102344267B1; TWI645966B; TW201532822A; CN106232355A

Abstract

　Provided is a mold-release polyimide film that serves as a material that can be used to manufacture a monolayer or multilayer wiring board having good planarity, that can obtain an insulating layer having good surface roughness in a semi-additive process, and that does not require etching after thermal pressing. Specifically provided is a mold-release polyimide film having a mold-release layer formed on at least one surface of a polyimide film, said mold-release layer containing an alkyd resin and an amino resin. Also provided is a method for manufacturing a multilayer wiring board, said method comprising: a step for manufacturing a monolayer or multilayer wiring board having a mold-release polyimide film having an adhesive layer by laminating a mold-release polyimide film, which has an adhesive layer on the surface of the mold-release layer to which the polyimide film is not provided, onto a monolayer or multilayer wiring board; a step for removing the mold-release polyimide film from the monolayer or multilayer wiring board having a mold-release polyimide film having an adhesive layer; and a step for performing circuit processing.

Description

Release polyimide film, laminate with release polyimide film with adhesive layer, laminate, single-layer or multilayer wiring board with release polyimide film with adhesive layer, and method for producing multilayer wiring board

The present invention relates to a release polyimide film, a laminate with a release polyimide film with an adhesive layer, a laminate, a single-layer or multilayer wiring board with a release polyimide film with an adhesive layer, and a method for producing a multilayer wiring board.

Conventionally, multilayer wiring boards are manufactured through a hot press process. This hot pressing step is a prepreg obtained by impregnating and coating a resin composition on a fiber substrate on a circuit board having an inner layer circuit on one side or both sides, or a resin film not containing a fiber substrate, and a copper foil. Are laminated, heated and pressurized. Moreover, the hot press process is often used because of its high productivity.

In recent years, with the miniaturization and high integration of electronic devices, there has been a demand for fine wiring of multilayer wiring board materials. As a method of forming fine wiring, after electroless copper plating is applied to the surface on which the circuit is to be formed, electrolytic copper plating is performed only on the necessary part, and the copper plating layer of the unnecessary part is removed by etching to form the wiring. The semi-additive method is preferably used. According to this method, as the thickness of the copper layer to be removed by etching is thinner, that is, by forming a plated copper layer thinly on the surface on which the circuit having a smaller surface roughness is formed and removing it, further fine wiring can be achieved. It becomes.

However, in the production of multilayer wiring boards using a hot press process, the copper foil is laminated between the surface on which the circuit is formed and the press board during the hot press process. It was necessary (see, for example, Patent Document 1). Further, since the surface roughness of the copper foil is transferred to the surface on which the circuit to be multilayered is formed, the surface roughness of the surface on which the circuit is formed is as large as about 0.3 μm.

In order to solve this, the use of a film material such as polyethylene terephthalate (PET) having a small surface roughness in place of the copper foil has been studied (for example, see Patent Document 2). There was room for further improvement from the influence on the insulating layer, which is a cured product of the resin film, due to thermal deformation.

Further, as a mold release agent for such a film material, a silicone mold release agent having excellent peelability is widely used.

JP 2003-251739 A Japanese Patent No. 5212578

However, when a silicone release agent is used, there is a problem that a low molecular weight component in the silicone composition is transferred to the insulating layer and causes a decrease in reliability.
In view of the current situation, the object of the present invention is that the etching after the hot pressing process, which was necessary when using copper foil, is unnecessary, and an insulating layer having a surface roughness suitable for the semi-additive method is obtained. It is an object of the present invention to provide a release polyimide film as a material capable of producing a multilayer wiring board having a small amount of transfer of a release agent component to an insulating layer and having good flatness.

As a result of intensive studies to achieve the above object, the present inventors have found that a polyimide film having a release layer shown below, that is, a release polyimide film, meets the above object, and the present invention. Reached.

That is, the present invention provides the following materials.
[1] A release polyimide film having a release layer containing an alkyd resin (A) and an amino resin (B) on at least one surface of the polyimide film.
[2] The release polyimide film according to [1], wherein the release layer has a thickness of 0.01 to 10 μm.
[3] The release polyimide film according to [1] or [2], wherein the polyimide film has a thickness of 10 to 100 μm.
[4] The release polyimide film according to any one of [1] to [3], wherein a surface roughness (Ra) of a surface of the polyimide film on which the release layer is formed is 0.2 μm or less.
[5] The release polyimide film according to any one of [1] to [4], which has an adhesive layer on a surface of the release layer where no polyimide film is provided.
[6] The release polyimide film according to [5], wherein the adhesive layer is made of a resin composition containing an epoxy resin and an epoxy resin curing agent.
[7] A laminate with a release polyimide film with an adhesive layer obtained by laminating the adhesive layer side of the release polyimide film according to [5] or [6] on at least one surface of a prepreg or an insulating layer.
[8] A laminate obtained by peeling off the release polyimide film of the laminate according to [7].
[9] The adhesive polyimide layer of the release polyimide film according to [5] or [6] is laminated on one surface of the prepreg or the insulating layer, and the other surface of the prepreg or the insulating layer is a single processed circuit. A monolayer or multilayer wiring board with a release polyimide film with an adhesive layer, which is laminated on a layer or a multilayer wiring board.
[10] A process for producing a single-layer or multilayer wiring board with a release polyimide film with an adhesive layer by laminating the release polyimide film according to [5] or [6] on a single-layer or multilayer wiring board; The manufacturing method of a multilayer wiring board including the process of removing a release polyimide film from a single layer with a release polyimide film with a layer, or a multilayer wiring board, and the process of processing a circuit.

According to the present invention, for example, when producing a multilayer wiring board by a molding method using a hot plate press, a roll laminator, a double press, etc., it is excellent in releasability from an insulating layer, and further, for example, 200 ° C. or more Insulating layer that has heat resistance that does not cause the film to melt even when used at high temperatures, has little transfer of the release agent component to the insulating layer, has low surface roughness, and excellent surface flatness A release polyimide film capable of obtaining a multilayer wiring board and a method for producing a multilayer wiring board using the same can be provided.

In Example 1, it is the result of having observed the surface state of the insulating layer after peeling a release polyimide film after a press with the high-precision three-dimensional surface shape roughness measuring system. In Comparative Example 3, the surface state of the insulating layer after the electrolytic copper foil on the surface was removed by etching was observed with a high-precision three-dimensional surface shape roughness measurement system.

[Release polyimide film]
First, the release polyimide film of the present invention will be described. The release polyimide film of the present invention has a release layer containing an alkyd resin (A) and an amino resin (B) on at least one surface of the polyimide film.
In the present specification, “contains” means that the contained product does not react and is contained as it is, and at least a part of the contained product is contained in a reacted state. It means that it may be in any state.
As the polyimide film used as the base material of the release polyimide film of the present invention, one having an appropriate strength and not causing tearing or the like when peeled is suitably used. For example, an aromatic polyimide in which aromatic compounds are directly linked by an imide bond is preferable in terms of film strength, and an aromatic polyimide having a structural unit represented by the following formula (I) is more preferable.

(In the formula (I), Z ¹ is a tetravalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and Z ² is a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.)

The tetravalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Z ¹ is preferably a tetravalent aromatic hydrocarbon group having 6 to 12 carbon atoms.
Preferred examples of the tetravalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Z ¹ include the following aromatic hydrocarbon groups.

Further, the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Z ² is preferably a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms.
Preferred examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Z ² include the following aromatic hydrocarbon groups.

Examples of commercially available polyimide films include Ube Industries, Ltd., trade names: Upilex R, Upilex S, Upilex SGA, Toray DuPont Co., Ltd., trade names: Kapton H, Kapton V, Kapton E, Kapton EN, Kapton ENZT. , Manufactured by Kaneka Chemical Co., Ltd., trade names: Apical AH, Apical NPI, and the like. In order to improve the adhesion to the release layer, the surface of these commercially available films may be subjected to, for example, plasma treatment, corona discharge treatment or the like.

The thickness of the polyimide film used as the substrate of the release polyimide film of the present invention may be selected depending on the purpose and application. From the viewpoint of the followability and peelability of the polyimide film, for example, the thickness of the polyimide film is preferably 10 to 100 μm, more preferably 20 to 50 μm, and more preferably 25 to 50 μm.

The surface roughness (Ra) of the polyimide film used as the substrate of the release polyimide film of the present invention is, for example, preferably 0.2 μm or less from the viewpoint of improving the flatness of the insulating layer after peeling. More preferably, it is 0.1 μm or less, and further preferably 0.05 μm or less. Here, “surface roughness of the polyimide film” indicates at least the surface roughness of the surface on the side where the release layer is formed.

The polyimide film according to the present invention has a strength that does not melt in a high temperature range, so that it is preferably used at 150 to 300 ° C., for example, and does not exhibit a clear glass transition temperature in the range, and further has a storage modulus ( 10 Hz) preferably exceeds 1 GPa.

(Release layer)
The resin composition for forming the release layer of the release polyimide film of the present invention (hereinafter sometimes referred to as a release layer resin composition) contains an alkyd resin (A) and an amino resin (B). It is a waste. In the solid content of the release layer resin composition, the total content of the alkyd resin (A) and the amino resin (B) (however, when an organic solvent is contained, the total content is the solid content). Is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass or more.
By making the release layer contain an alkyd resin (A) and an amino resin (B), a crosslinked structure is obtained in the release layer, and the release layer is compared with a silicone release agent. Migration of the resin composition component for an insulating layer to the insulating layer is suppressed, and good releasability is exhibited. By suppressing the transfer of the resin composition component for the release layer to the insulating layer, it is possible to suppress a decrease in heat resistance or the like of the insulating layer.
For example, the thickness of the release layer is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and further preferably 0.05 to 2 μm. When the release layer has a thickness of 0.01 to 10 μm, the peelability tends to be improved.
The ratio (A / B) of the component (A) to the component (B) is preferably, for example, 95/5 to 10/90, and 90/10 to 40/60 in terms of solid content. It is more preferable.
When the ratio of the alkyd resin (A) is 95% by mass or less (that is, the ratio of the amino resin (B) is 5% by mass or more), a sufficient crosslinked structure is obtained in the release layer, and the peelability is reduced. It tends to be suppressed. Further, when the ratio of the alkyd resin (A) is 10% by mass or more (that is, the ratio of the amino resin (B) is 90% by mass or less), the release layer does not become too hard, and good peelability is obtained. There is a tendency.

In the present invention, the alkyd resin (A) refers to a synthetic resin obtained by a condensation reaction between a polyhydric alcohol and a polybasic acid. As the alkyd resin (A), a conversion product which is a condensate of a dibasic acid and a dihydric alcohol or an inconvertible alkyd modified with a non-drying oil fatty acid, and a condensate of a dibasic acid and a trihydric or higher alcohol. Any of the alkyds can be used.
In addition, as the alkyd resin (A) used in the present invention, various commercially available resins may be used, or they may be synthesized according to a known method.

Examples of the method for synthesizing the alkyd resin (A) include a method in which a polyhydric alcohol and a polybasic acid or a modifier is added thereto and subjected to heat condensation.
Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, and neopentyl glycol; trivalent compounds such as glycerin, trimethylolethane, and trimethylolpropane. Alcohol; polyhydric alcohols such as diglycerin, triglycerin, pentaerythritol, pentaerythritol, dipentaerythritol, mannitol and sorbit can be used.

Examples of the polybasic acid include saturated polybasic acids such as phthalic anhydride, terephthalic acid, succinic acid, adipic acid, and sebacic acid; maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic anhydride, and isophthalic acid. Unsaturated polybasic acids such as acid and trimellitic anhydride; use of polybasic acids by Diels-Alder reaction such as cyclopentadiene-maleic anhydride adduct, terpene-maleic anhydride adduct, rosin-maleic anhydride adduct, etc. it can. In addition, you may use a benzoic acid together.

Examples of the modifier include coconut oil, linseed oil, tung oil, castor oil, dehydrated castor oil, and fatty acids thereof, octylic acid, lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and linoleic acid. Eleostearic acid, ricinoleic acid, dehydrated ricinoleic acid and the like can be used.

The oil length (fatty acid content mass ratio) of the alkyd resin (A) is preferably, for example, 0 to 60%, and more preferably 20 to 40%.
The acid value of the alkyd resin (A) is, for example, preferably 1 to 30 mgKOH / g, and more preferably 5 to 25 mgKOH / g.
Further, the hydroxyl value of the alkyd resin (A) is, for example, preferably 50 to 300 mgKOH / g, and more preferably 100 to 250 mgKOH / g.
Further, these alkyd resins (A) can be used by modifying or mixing, for example, acrylic resin, polyester resin, epoxy resin, phenol resin and the like.

In the present invention, the amino resin (B) refers to a resin obtained by a condensation reaction between a compound containing an amino group and an aldehyde, and examples thereof include a melamine resin, an aniline aldehyde resin, a urea resin, and a benzoguanamine resin.
As the amino resin used in the present invention, various commercially available amino resins may be used, or they may be synthesized according to known methods.
As a synthesis method, for example, various amino resins synthesized using a prepolymer containing methylol or an ether thereof as a raw material resin can be used.
More specifically, various well-known things, such as methylated melamine resin, butylated melamine resin, methylated urea resin, butylated urea resin, methylated benzoguanamine resin, butylated benzoguanamine resin, can be used. From the viewpoint of repeated usability, a methylated melamine resin, in particular, a methylated melamine resin containing at least one methylol group per triazine nucleus as a main component is preferable.
In the present invention, a methylated melamine resin that is particularly preferably used as an amino resin is usually obtained by subjecting melamine to an addition reaction of formalin under basicity and further subjecting methanol to an ether reaction under acidic conditions. The amount of imino group, methylol group, and methyl ether group, which are functional groups of the amino resin, can be controlled by the difference in the amount of formalin added and the amount of etherified methanol.
The amount of methylol group per triazine nucleus can be calculated by titration analysis and instrumental analysis. For example, it can be calculated by measuring with a nuclear magnetic resonance apparatus or elemental analysis apparatus.

Further, in the present invention, the release layer resin composition contains a silicone resin (C) from the viewpoint of releasability within a range where the migration of the release layer resin composition component to the insulating layer is suppressed. Also good.
In that case, the content ratio of the silicone resin is such that the content ratio (C / (A + B)) of the silicone resin (C) to the total content of the alkyd resin (A) and the amino resin (B) is a solid content mass ratio. It is preferably 20/100 or less, and more preferably 10/100 or less. When the component (C) is 20 parts by mass or less with respect to a total of 100 parts by mass of the component (A) and the component (B), good curability is obtained, and migration of the silicone resin (C) occurs. It tends to be difficult.
In the present invention, the silicone resin (C) refers to organopolysiloxane, silicone rubber, and silicone oil having a three-dimensional network structure mainly composed of dimethylpolysiloxane. As the silicone resin (C) used in the present invention, various commercially available resins may be used, or they may be synthesized according to known methods.

As the silicone resin (C), organopolysiloxane is preferable, and any structure of linear or branched structure can be used as long as a release layer excellent in heat resistance, gloss, releasability and surface condition can be obtained. However, those having excellent compatibility with the alkyd resin (A) and the amino resin (B) are preferably used for the resin composition for a release layer of the present invention.
The organopolysiloxane can change properties such as flexibility and elasticity of the resin by changing the molar ratio between the organic group and the silicon atom. Specifically, as such an organopolysiloxane, the following formula (1):

(In the formula, at least one of R ¹ is a substituent having reactivity with at least one of alkyd resin and amino resin (including a reaction product of alkyd resin and amino resin), and the remainder is carbon number. 1 to 12 unsubstituted or substituted alkyl groups, X is 15 to 500, preferably 25 to 100, Y is 15 to 500, preferably 25 to 100, and X + Y is 30 to 1000, preferably 50 to 200. 0.15 ≦ Y / (X + Y) ≦ 0.5.).
The organic group bonded to the silicon atom in one molecule of the organopolysiloxane is preferably 15 to 50 mol%, more preferably 15 to 40 mol%. When the amount of the phenyl group is 15 mol% or more, the compatibility with the alkyd resin (A) and the amino resin (B) tends to be good. Moreover, it exists in the tendency for the fall of peelability to be suppressed as the amount of phenyl groups is 50 mol% or less.

In order for the release layer to have sufficient peelability, at least one of the remaining organic groups other than the phenyl group is a functional group that is reactive with at least one of the alkyd resin and the amino resin. Is preferred. Examples of the functional group reactive with at least one of the alkyd resin and amino resin include a hydroxyl group-substituted organic group, an amino group-substituted organic group, a carboxyl group-substituted organic group, and a glycidyl group-substituted organic group. Among these, a hydroxyl group-substituted organic group is preferable from the viewpoint of ease of introduction into an aminoalkyd resin.

When a hydroxyl group-substituted organic group is used, 1 to 20 hydroxyl group-substituted organic groups are preferably contained per silicone resin molecule, more preferably 1 to 10 groups. Examples of the hydroxyl group-substituted organic group include the following formula (2):

(Wherein n is an average value of 1 to 3) and a hydroxyl group-substituted organic group represented by the following formula (3):

(Wherein R and R ² are divalent hydrocarbon groups having 1 to 10 carbon atoms, and a is 0 or 1), and the like.

By having a substituent having reactivity with at least one of such alkyd resin and amino resin, a structure in which at least one of alkyd resin and amino resin reacts with silicone resin and chemically bonded in the release layer is obtained. In addition, it is possible to suppress the transfer of silicone to the insulating layer while improving the peelability.

The remaining unsubstituted or substituted alkyl group other than the organic group includes a linear alkyl group or a branched alkyl group having 1 to 12, preferably 1 to 8, more preferably 1 to 5 carbon atoms. Examples of the alkyl group include an unsubstituted alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, and an octyl group, or a carbon atom of these groups. Examples thereof include substituted alkyl groups such as a chloromethyl group, a trifluoropropyl group, and a cyanoethyl group in which part or all of the hydrogen atoms are substituted with halogen atoms such as fluorine, chlorine, bromine, and iodine, and cyano groups. In addition, it is preferable that it is a methyl group from a viewpoint of obtaining higher peelability.

A surfactant can be blended in the release layer resin composition used in the present invention.
In the present invention, the term “surfactant” refers to a substance that exhibits surface activity even at a low concentration, which is used to control interfacial phenomena. Surfactants include anionic surfactants whose main active agent is an anion, cationic surfactants whose main active agent is a cation, amphoteric surfactants whose main active agent is amphoteric, ionization However, a cationic surfactant having antistatic properties is preferred from the standpoint of effects.

Examples of the cationic surfactant include quaternary ammonium salts, tertiary ammonium salts, amide quaternary ammonium salts, and the like. In order to further enhance the antistatic effect, a quaternary ammonium salt is preferred. Examples of the quaternary ammonium salt include alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium salt, tetraalkyl ammonium salt, alkyl dimethyl benzyl ammonium salt, alkyl pyridinium salt, alkyl morpholinium salt, alkyl imidazolinium salt, amido ammonium salt. 5,5,7,7-tetramethyl-2-octenylmethylammonium chloride, quaternary ammonium salt of polyethyleneimine, benzyl tri (dimethylamino) phosphonium chloride, hexadecyl tri (dimethylamino) phosphonium chloride, etc. Can be mentioned.

The addition amount of the cationic surfactant is 0.05 to 10 parts by mass, preferably 0. 10 parts by mass with respect to 100 parts by mass of the composition comprising the alkyd resin (A), amino resin (B), and silicone resin (C). 1 to 5 parts by mass. When the addition amount is 0.05 parts by mass or more, good antistatic performance tends to be obtained. Moreover, when the addition amount is 10 parts by mass or less, good curability of the coating film is obtained, and a decrease in peelability tends to be suppressed. In the present invention, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used in combination with the cationic surfactant as long as the effects of the present invention are exhibited. Examples of the anionic surfactant include alkyl phosphate salts, alkyl sulfone hydrochloride, alkyl benzene sulfonate, and the like. Nonionic surfactants include, for example, glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene alkylamine fatty acid ester, N-hydroxyethyl-N-2-hydroxyalkylamine, alkyldiethanolamide and the like. Can be mentioned. Examples of amphoteric surfactants include alkyl betaines and alkyl imidazolinium betaines. Various commercially available surfactants may be used as the cationic surfactant, nonionic surfactant, anionic surfactant, and amphoteric surfactant.

In the present invention, the release layer resin composition may contain an acidic catalyst. The acidic catalyst functions as a catalyst for the reaction between the alkyd resin (A) and the amino resin (B). By using an acidic catalyst, coating at a low temperature is possible, and productivity is improved. Examples of the acidic catalyst include p-toluenesulfonic acid, oxalic acid, phosphoric acid and the like.

The reason why the silicone resin (C) containing a functional group reactive with at least one of the alkyd resin (A) and the amino resin (B) is introduced into the release layer resin composition is to adjust the peelability. It is. In addition, when not introducing a silicone resin, the coating property at the time of forming an adhesive layer on a mold release layer becomes favorable.
In addition, the resin composition (henceforth a silicone containing amino alkyd resin and an alkyd resin (A), an amino resin (B), and the silicone resin which has a functional group reactive with the compound which made the alkyd resin react with an amino resin) Can also be purchased commercially. For example, trade names, Tesfine 319, TA31-209E, etc., manufactured by Hitachi Chemical Polymer Co., Ltd. can be mentioned.
A resin composition containing an alkyd resin and an amino resin (hereinafter also referred to as non-silicone amino alkyd resin) can be purchased commercially. For example, trade names, Tesfine 303, Tesfine 305, etc., manufactured by Hitachi Chemical Polymer Co., Ltd. may be mentioned.

It is preferable that the release layer resin composition is finally in a state of a varnish in which each component is dissolved or dispersed in an organic solvent (hereinafter sometimes referred to as a release layer resin varnish).

Examples of the organic solvent used for forming the varnish include alcohol solvents such as methanol, ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Ester solvents such as butyl acetate and propylene glycol monomethyl ether acetate; ether solvents such as tetrahydrofuran; aromatic solvents such as toluene, xylene and mesitylene; dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. Nitrogen atom-containing solvents; sulfur atom-containing solvents such as dimethyl sulfoxide. These can be used individually by 1 type or in mixture of 2 or more types.
Among these, for example, an aromatic solvent and a ketone solvent are preferable from the viewpoint of solubility and appearance at the time of coating, and a mixed solvent of toluene and methyl ethyl ketone (MEK) is more preferable.

The content (solid content concentration) of the resin composition in the finally obtained varnish is, for example, preferably 1 to 40% by mass, more preferably 5 to 30% by mass, based on the entire varnish. By controlling the content (solid content concentration) of the resin composition in the varnish to 1 to 40% by mass, the film thickness during coating can be easily controlled.

Further, if necessary, an easy lubricant, an antistatic agent, etc. can be added to the release layer, that is, to the release layer resin composition. In the hot pressing step, static electricity frequently occurs, so a method of adding an antistatic agent is preferable, and the antistatic layer may be formed by application to a surface on which no release layer is formed.

As a method for forming a release layer having a desired thickness on at least one surface of the polyimide film, a reverse roll coater, a gravure coater, a rod coater, an air doctor coater, or the like is used on the polyimide film, for example, 50 Examples include a method of drying at a temperature of from 200 ° C. to 200 ° C. for 10 seconds to 600 seconds.

(Adhesive layer)
The release polyimide film of the present invention can have an adhesive layer on the surface of the release layer where no polyimide film is provided.
The adhesive layer may be formed on the release layer surface using a resin composition containing an epoxy resin and an epoxy resin curing agent (hereinafter sometimes referred to as a resin composition for an adhesive layer). preferable. Epoxy resins are preferred because they are excellent in heat resistance, alkali resistance, and the like. In addition, the resin composition “comprising an epoxy resin and an epoxy resin curing agent” may contain an epoxy resin and an epoxy resin curing agent in an unreacted state or in a reacted state. It may be.
The thickness of the adhesive layer is preferably from 0.01 to 10 μm, more preferably from 0.05 to 8 μm. By setting it within this range, it is possible to more easily remove the release polyimide film at the interface between the adhesive layer and the release layer after hot plate pressing.
Here, the “epoxy resin” is an epoxy resin having two or more epoxy groups in the molecule. Examples of the resin having two epoxy groups in the molecule include bisphenol A type epoxy resin and bisphenol F type epoxy resin. Moreover, you may use the polyfunctional epoxy resin which has an epoxy group larger than two on average in a molecule | numerator.
Examples of the polyfunctional epoxy resin include biphenyl aralkyl type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, aralkyl type epoxy resins, naphthalene type epoxy resins, naphthalene novolak type epoxy resins and the like. Among these, as the polyfunctional epoxy resin, for example, an aralkyl novolac epoxy resin and a naphthalene novolac epoxy resin are preferable. Moreover, from the viewpoint of adhesive strength with plated copper, the polyfunctional epoxy resin of the adhesive layer preferably has, for example, a biphenyl structure.
These may be used alone or in admixture of two or more.
Among these, for example, an aralkyl novolak type epoxy resin having a biphenyl structure (biphenyl aralkyl type epoxy resin) is preferable. Examples of commercially available aralkyl novolak epoxy resins having a biphenyl structure include NC-3000 and NC-3000-H manufactured by Nippon Kayaku Co., Ltd.

Examples of the epoxy resin curing agent include polyfunctional phenol compounds such as phenol novolak and cresol novolac; amine compounds such as dicyandiamide, diaminodiphenylmethane and diaminodiphenylsulfone; phthalic anhydride, pyromellitic anhydride, maleic anhydride, anhydrous Examples thereof include acid anhydrides such as maleic acid copolymers. These 1 type (s) or 2 or more types can be mixed and used.

The resin composition for an adhesive layer may contain a curing accelerator. As the curing accelerator, for example, various imidazoles that are latent thermosetting agents, BF ₃ amine complexes, and phosphorus-based curing accelerators can be used.
The blending amount of the curing accelerator is preferably 0.1 to 5% by mass with respect to the blending amount of the epoxy resin.
From the viewpoint of storage stability of the adhesive layer resin composition, handling property of the B-stage (semi-cured) adhesive layer resin composition, and solder heat resistance, imidazoles and phosphorus curing accelerators are preferable.

Examples of imidazoles include 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1,2-dimethylimidazole, 2-ethyl-1-methylimidazole, 1, 2-diethylimidazole, 1-ethyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2 -Fe 4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 2,4-diamino-6 -[2'-methylimidazolyl- (1 ')] ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')] ethyl-s-triazine, 2,4- Imidazole compounds such as diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)] ethyl-s-triazine; addition reaction product of the imidazole compound and trimellitic acid; the imidazole compound and isocyanuric acid; Addition reaction product of imidazole compound and hydrobromic acid; addition reaction product of imidazole compound and epoxy resin; imida Such as addition reaction product of an Lumpur compound and cyanate resins. Among these, 2-phenylimidazole and 2-ethyl-4-methylimidazole are preferable.

As the phosphorus-based curing accelerator, a curing accelerator that contains a phosphorus atom and accelerates the curing reaction of the epoxy resin is preferable. For example, a phosphorus curing accelerator may be used alone, or one or more other curing accelerators may be used in combination. Examples of phosphorus curing accelerators include triphenylphosphine, diphenyl (alkylphenyl) phosphine, tris (alkylphenyl) phosphine, tris (alkoxyphenyl) phosphine, tris (alkylalkoxyphenyl) phosphine, tris (dialkylphenyl) phosphine, Tris (trialkylphenyl) phosphine, tris (tetraalkylphenyl) phosphine, tris (dialkoxyphenyl) phosphine, tris (trialkoxyphenyl) phosphine, tris (tetraalkoxyphenyl) phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiaryl Organic phosphines such as phosphine; Complexes of these organic phosphines and organic borons; Addition of tertiary phosphine and quinones And the like.

Furthermore, the resin composition for an adhesive layer of the present invention can be arbitrarily selected from known inorganic fillers, organic fillers, thermoplastic resins, flame retardants, ultraviolet absorbers, antioxidants, photopolymerization initiators, depending on the purpose. A fluorescent brightener, an adhesion improver, etc. can be used.

Examples of inorganic fillers include silica, alumina, talc, mica, kaolin, aluminum hydroxide, boehmite, magnesium hydroxide, zinc borate, zinc stannate, zinc oxide, titanium oxide, boron nitride, calcium carbonate, and barium sulfate. In addition to aluminum borate and potassium titanate, glass powder such as E glass, T glass, D glass, or hollow glass beads can be used. These may be used alone or in admixture of two or more.
As content of an inorganic filler, it is preferable that it is 10 mass% or less in the resin composition for contact bonding layers. When the blending amount is 10% by mass or less, a good surface shape after the roughening treatment can be maintained, and deterioration of plating characteristics and interlayer insulation reliability can be prevented.

Examples of the organic filler include resin particles having a uniform structure made of polyethylene, polypropylene, polystyrene, polyphenylene ether resin, silicone resin, tetrafluoroethylene resin, etc .; acrylate ester resins, methacrylate ester resins, conjugated diene resins And a core-shell resin particle having a glassy shell layer made of an acrylic ester resin, a methacrylic ester resin, an aromatic vinyl resin, a vinyl cyanide resin, etc. Can be mentioned.
The content of the organic filler is, for example, preferably 0.5 to 300 parts by mass, and more preferably 1 to 250 parts by mass with respect to 100 parts by mass of the total resin components.

Examples of the thermoplastic resin include polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, xylene resin, petroleum resin, and silicone resin.

Examples of the flame retardant include halogen-containing flame retardants containing bromine and chlorine; phosphorus flame retardants such as triphenyl phosphate, tricresyl phosphate, trisdichloropropyl phosphate, phosphate ester compounds, red phosphorus; sulfamic acid Nitrogen flame retardants such as guanidine, melamine sulfate, melamine polyphosphate and melamine cyanurate; phosphazene flame retardants such as cyclophosphazene and polyphosphazene; and inorganic flame retardants such as antimony trioxide.

Other examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers. Examples of the antioxidant include hindered phenol-based and hindered amine-based antioxidants. Examples of the photopolymerization initiator include benzophenones, benzyl ketals, and thioxanthone photopolymerization initiators. Examples of the fluorescent brightener include stilbene derivatives. Examples of the adhesion improver include urea compounds such as urea silane; coupling agents such as silane, titanate, and aluminate.

The resin composition for the adhesive layer is preferably finally in a state of a varnish in which each component is dissolved or dispersed in an organic solvent (hereinafter, sometimes referred to as a resin varnish for the adhesive layer).

Examples of the organic solvent used for forming the varnish include alcohol solvents such as methanol, ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Ester solvents such as butyl acetate and propylene glycol monomethyl ether acetate; ether solvents such as tetrahydrofuran; aromatic solvents such as toluene, xylene and mesitylene; dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. A nitrogen atom-containing solvent; a sulfur atom-containing solvent such as dimethyl sulfoxide and the like can be mentioned, and one kind can be used alone or two or more kinds can be mixed and used.
These organic solvents are appropriately selected from the viewpoint of the solubility of the resin and the appearance after coating.
Among these, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; nitrogen atom-containing solvents such as dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone; ketone solvents and nitrogen atom-containing solvents; These mixed solvents are preferred from the viewpoint of the solubility of the resin and the appearance after coating.

The resin composition in the varnish finally obtained is, for example, preferably 1 to 60% by mass, more preferably 2 to 50% by mass with respect to the entire varnish. The content of the resin composition in the varnish is preferably 1 to 60% by mass from the viewpoint of film thickness accuracy during coating and appearance.

The adhesive layer of the present invention is a coating of a reverse coater, gravure coater, air doctor coater, die coater, lip coater, etc. on the release layer of the release polyimide film with the resin composition for the adhesive layer (or the varnish containing it). For example, it can be obtained by drying at 80 to 230 ° C. for 30 seconds to 600 seconds using an apparatus.

In the present invention, an adhesive layer may be provided on the surface of the release polyimide film where the release layer is not provided, and in this state, it can also be used in a hot plate pressing step.

By using the release polyimide film of the present invention, the surface flatness of the insulating layer after the hot pressing process is improved. As shown in the result of observing the surface state of the insulating layer in FIGS. 1 and 2 with a high-precision three-dimensional surface shape roughness measurement system, the surface flatness is obtained when the copper foil shown in FIG. 2 is used. In the case of using the release polyimide film of the present invention, almost no undulation is seen as shown in FIG. This swell is presumed to be caused by a difference in thermal expansion coefficient between an insulating layer having a low thermal expansion coefficient and a copper foil having a high thermal expansion coefficient during the hot pressing process.

[Laminate with Release Polyimide Film with Adhesive Layer, Laminate by Exfoliating Release Polyimide Film of Laminate, Single or Multilayer Wiring Board with Release Polyimide Film with Adhesive Layer, and Manufacturing Method of Multilayer Wiring Board]
The laminated board with a release polyimide film with an adhesive layer of the present invention is formed by laminating the adhesive layer side of the release polyimide film with an adhesive layer on at least one surface of a prepreg or an insulating layer.

The laminated plate with a release polyimide film with an adhesive layer of the present invention is obtained by stacking a release polyimide film with an adhesive layer on one or both sides of a prepreg or an insulating layer so that the adhesive layer is on the inside, and further stacking an end plate on the outside. Can be press-molded and manufactured.
Moreover, the laminated board with a release polyimide film with an adhesive layer of the present invention is formed by, for example, stacking a release polyimide film with an adhesive layer on one side or both sides of a prepreg or an insulating layer so that the adhesive layer is on the inside. It can be manufactured by heating and pressurizing with a laminator using a sheet and then heating and curing after the lamination.

The heating temperature (temperature of the hot plate) in the press molding is preferably 150 to 260 ° C. The pressure during the pressurization is preferably 0.5 to 10 MPa. Further, the heating temperature in the laminator using the heat resistant rubber sheet is preferably 80 to 150 ° C. The pressure during pressurization is preferably 0.3 to 10 MPa.
In any method, after the lamination molding, the release polyimide film can be appropriately peeled off to obtain a laminate.

The single-layer or multilayer wiring board with the release polyimide film (release polyimide film with an adhesive layer) of the present invention is laminated on one side of the prepreg or insulating layer of the release polyimide film with an adhesive layer, The other surface of the prepreg or insulating layer is laminated on a single-layer or multilayer wiring board formed by circuit processing. The prepreg may be a prepreg before curing, or a prepreg that is at least partially cured.
Here, “being circuit-processed” includes a case where a process that can be normally performed in the manufacture of a wiring board is performed after the circuit is processed. Specifically, after the circuit is processed, plating is performed. Including cases where processing is performed. A single-layer wiring board refers to a wiring board having a single circuit layer when a prepreg or insulating layer is laminated on only one side, and when a prepreg or insulating layer is laminated on both sides. Each of the wiring boards has one circuit layer (that is, a total of two circuit layers). On the other hand, a multilayer wiring board is a core on which at least one surface is processed, and at least one prepreg or insulating layer is laminated on the surface of the core on which the circuit is processed. The circuit is processed on the layer.

The manufacturing method of the multilayer wiring board of this invention manufactures the single layer or multilayer wiring board with a release polyimide film with an adhesive layer by laminating | stacking the release polyimide film which has the said contact bonding layer on a single layer or a multilayer wiring board. Including a step, a step of removing the release polyimide film from the single-layer or multilayer wiring board with the release polyimide film with an adhesive layer, and a step of circuit processing. Here, as a method for producing a release polyimide film having an adhesive layer, a release agent composition containing an alkyd resin (A) and an amino resin (B) is applied on one surface of the polyimide film and released. A step of forming a layer (release polyimide film manufacturing step), a step of forming an adhesive layer on the surface of the release layer where the polyimide film is not provided, and manufacturing a release polyimide film having the adhesive layer (adhesive layer) It is preferable to include an attached mold release polyimide film manufacturing process).
Among the above processes, the release polyimide film manufacturing process and the release polyimide film manufacturing process with an adhesive layer are as described above.
Below, a single layer or multilayer wiring board manufacturing process with a release polyimide film with an adhesive layer and a release polyimide film removal process will be described.
In addition, after removing a release polyimide film from a single layer with a release polyimide film with an adhesive layer or a multilayer wiring board, the adhesive layer functions as an insulating layer of the multilayer wiring board.

In the production process of a single layer or multilayer wiring board with a release polyimide film with an adhesive layer, for example, first, the release polyimide film of the present invention having an adhesive layer formed thereon is used as a prepreg or an insulating layer so that the adhesive layer is on the inside. The circuit board is overlaid on one side or both sides of the circuit board. Furthermore, the end plate is stacked on the outside and press-molded. By removing the end plate, a single-layer or multilayer wiring board in which the release polyimide film of the present invention is disposed on one side or both sides is manufactured. Thereafter, the release polyimide film of the present invention is peeled and removed (release polyimide film removal step), and a multilayer wiring board is obtained through a circuit processing step.

The heating temperature (temperature of the hot plate) in the press molding is preferably 180 to 300 ° C., and more preferably 200 to 250 ° C., for example. The pressure during pressurization is preferably 1 to 4 MPa.

In addition, it is also possible to remove a mold release polyimide film after performing a drill process and a laser process from the upper surface of a polyimide film before peeling (mold release polyimide film removal process) as needed. By drilling from the upper surface of the polyimide film, resin scattering during processing is prevented, and the yield is significantly improved.

Here, as a material of the prepreg and the insulating layer used in the method for manufacturing a multilayer wiring board of the present invention, a generally used material that is not particularly limited can be applied. For example, a polyfunctional epoxy resin, an epoxy resin curing agent, a curing accelerator, a solvent and, if necessary, a mixture of inorganic fillers may be used as the material for the insulating layer, and further, the glass cloth for laminated plates may be impregnated or A prepreg obtained by coating may be used. Commercially available products may be used as the prepreg, and examples of commercially available products include GEA-67N, GEA-679F, GEA-679GT, and GEA-700G manufactured by Hitachi Chemical Co., Ltd.

An inner layer circuit board in a single-layer wiring board or multilayer wiring board formed by circuit processing is, for example, an inner layer board on which a first circuit layer (inner layer wiring) is formed, and an ordinary wiring board as an inner layer board There are no particular restrictions on the known laminates used in U.S.A. such as glass cloth-epoxy resin, paper-phenol resin, paper-epoxy resin, glass cloth or glass paper-epoxy resin. Further, a BT substrate impregnated with a bismaleimide-triazine resin, a polyimide film substrate using a polyimide film as a base material, and the like can also be used.

There is no particular limitation on the method of forming the circuit. For example, a known circuit forming method such as a semi-additive method in which a circuit is formed using a plating process or an additive method in which a circuit is formed by electroless plating at a necessary portion of an insulating substrate can be used.

When circuit processing is carried out by a plating process on the laminate of the present invention or the adhesive layer of a single layer or multilayer wiring board, first, roughening is performed. Examples of the roughening liquid in this case include an oxidizing roughening liquid such as a chromium / sulfuric acid roughening liquid, an alkaline permanganic acid roughening liquid, a sodium fluoride / chromium / sulfuric acid roughening liquid, and a borofluoric acid roughening liquid. Can be used. As the roughening treatment, for example, as a swelling liquid, an aqueous solution of diethylene glycol monobutyl ether and NaOH is first heated to 70 ° C., and the laminate or single layer or multilayer wiring board is immersed for 5 minutes. Next, as a roughening solution, an aqueous solution of KMnO ₄ and NaOH is heated to 80 ° C. and immersed for 10 minutes. Subsequently, neutralizing solution, for example, a method of neutralizing by immersion for 5 minutes at room temperature to an aqueous hydrochloric acid solution of stannous chloride (SnCl ₂₎ and the like.

After the roughening treatment, a plating catalyst application treatment for adhering palladium is performed. The plating catalyst treatment is performed by immersing in a palladium chloride plating catalyst solution. Next, an electroless plating treatment is performed in which an electroless plating layer (conductor layer) having a thickness of 0.3 to 1.5 μm is deposited on the entire surface of the plating process primer layer by dipping in an electroless plating solution.
Next, after forming a plating resist, electroplating is performed to form a circuit with a desired thickness at a desired location. As the electroless plating solution used for the electroless plating treatment, a known electroless plating solution can be used, and there is no particular limitation. As the plating resist, a known plating resist can be used, and there is no particular limitation. Also, the electroplating treatment can be performed by a known method and is not particularly limited. These platings are preferably copper platings. Furthermore, the outer layer circuit can be formed by etching away the electroless plating layer at unnecessary portions.

If necessary, the surface of the circuit layer is surface-treated in a state suitable for adhesion, but this method is not particularly limited. For example, a copper oxide needle crystal is formed on the surface of the circuit layer 1 with an alkaline aqueous solution of sodium hypochlorite, and the formed copper oxide needle crystal is immersed in a dimethylamine borane aqueous solution for reduction. Manufacturing methods can be used.

Hereinafter, a multilayer wiring board having a large number of layers can be manufactured by repeating the same process.

Next, the present invention will be described with reference to examples, but the scope of the present invention is not limited to these examples.

[Preparation of resin varnish for adhesive layer]
(Preparation Example 1)
Add 22.5 g of phenol aralkyl resin (Mitsui Chemicals, trade name: XLC-LL) to 27.5 g of cresol novolac type epoxy resin (trade name: YDCN-700-10, manufactured by Nippon Kayaku Epoxy Manufacturing Co., Ltd.) 850 g of cyclohexanone was added and stirred and kneaded. Acrylic rubber (manufactured by Nagase ChemteX Corporation, trade name: HTR-860P-3, weight average molecular weight 800,000, glass transition point: 13 ° C.) 100 g, 1-cyanoethyl-2-phenylimidazole (Shikoku) as a curing accelerator 0.25 g (trade name: Curesol 2PZ-CN) manufactured by Kasei Kogyo Co., Ltd. was added and stirred to obtain a resin varnish A for adhesive layer (solid content concentration of about 15% by mass).
(Preparation Example 2)
After blending 159 g of N, N-dimethylacetamide (DMAc) with 18 g of polyamide (manufactured by Nippon Kayaku Co., Ltd., trade name: BPAM-155), biphenylaralkyl epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product) Name: NC3000H) 50 g, bisphenol A novolak type phenolic resin (Mitsubishi Chemical Co., Ltd., trade name: YLH129) 20 g, and 2-phenylimidazole (Shikoku Kasei Kogyo Co., Ltd., trade name: 2PZ) as a curing accelerator. After adding 0.5 g and diluting with a mixed solvent consisting of DMAc and methyl ethyl ketone, 5 g of alumina filler (CAI Kasei Co., Ltd., trade name: NanoTek) is added, and a disperser (Yoshida Kikai Kogyo Co., Ltd., trade name: Resin varnish B for adhesive layer (solid content concentration of about 25) using Nanomizer To give the amount%).

[Preparation of resin varnish for release layer]
(Preparation Example 3)
Non-silicone amino alkyd resin [Tesfine 303, manufactured by Hitachi Chemical Co., Ltd., solid content 48.7%] 31.5 g, p-toluenesulfonic acid [Dryer 900, manufactured by Hitachi Chemical Polymer Co., Ltd. Min. 50%] was mixed, and then diluted with 1050 g of toluene and 450 g of MEK to obtain a release layer resin varnish A.
(Preparation Example 4)
Non-silicone amino alkyd resin [Tesfine 305, manufactured by Hitachi Chemical Co., Ltd., trade name, solid content 48.7%] 31.5 g, p-toluenesulfonic acid [Dryer 900, Hitachi Chemical Polymer Co., Ltd.] as an acidic catalyst Manufactured, trade name), solid content 50%], and then diluted with 1050 g of toluene and 450 g of MEK to obtain a resin varnish B for a release layer.
(Preparation Example 5)
Silicone-containing amino alkyd resin [Tesfine 319, manufactured by Hitachi Chemical Co., Ltd., solid content 48.7%] 31.5 g, p-toluenesulfonic acid [Dryer 900, manufactured by Hitachi Chemical Polymer Co., Ltd. , 50% solid content], and then diluted with 1050 g of toluene and 450 g of MEK to obtain a release layer resin varnish C.
(Preparation Example 6)
Silicone-containing aminoalkyd resin [TA31-209E, manufactured by Hitachi Chemical Co., Ltd., trade name, solid content 48.7%] 31.5 g, p-toluenesulfonic acid [Dryer 900, manufactured by Hitachi Chemical Polymer Co., Ltd.] as an acidic catalyst , Trade name, solid content 50%], and then diluted with 1050 g of toluene and 450 g of MEK to obtain a resin varnish D for a release layer.

Example 1
・ Release polyimide film with adhesive layer:
Ube Industries, Ltd., Upilex 25SGA (trade name), thickness of 25 μm, and surface roughness Ra of less than 0.05 μm were used as the polyimide film. On this polyimide film, the resin varnish A for release layer prepared in Preparation Example 3 was applied using a die coater and dried at 160 ° C. for 40 seconds to obtain a release layer having a thickness of 0.2 μm.
The adhesive layer resin varnish A prepared in Preparation Example 1 is applied to the release layer surface of the obtained release polyimide film, dried at 140 ° C. for 5 minutes to form an adhesive layer having a thickness of 5 μm, and an adhesive layer is provided. A release polyimide film was obtained.

・ Laminated board:
Four prepregs (manufactured by Hitachi Chemical Co., Ltd., GEA-700G, product name, 0.10 mm thickness) are stacked, and the upper and lower layers are stacked so that the polyimide film surface of the release polyimide film with the adhesive layer is on the outside. And the cushion paper was piled up, and it heat-cured at 3.0 MPa and 240 degreeC for 1 hour using the press machine, and obtained the laminated board.

(Example 2)
As the polyimide film, a release polyimide film with an adhesive layer and a laminated board were used in the same manner as in Example 1 except that Kapton 100H (trade name) manufactured by Toray DuPont Co., Ltd., thickness 25 μm, surface roughness Ra less than 0.05 μm was used. Obtained.

Example 3
Release layer with adhesive layer as in Example 1, except that the resin varnish B for release layer prepared in Preparation Example 4 was used as the release layer and the varnish B for adhesive layer prepared in Preparation Example 2 was used as the adhesive layer. A polyimide film and a laminate were obtained.

Example 4
Release layer with adhesive layer as in Example 1, except that the resin varnish C for release layer prepared in Preparation Example 5 was used as the release layer, and the varnish B for adhesive layer prepared in Preparation Example 2 was used as the adhesive layer. A polyimide film and a laminate were obtained.

(Example 5)
Release layer with adhesive layer as in Example 1 except that the resin varnish D for release layer prepared in Preparation Example 6 was used as the release layer, and the varnish B for adhesive layer prepared in Preparation Example 2 was used as the adhesive layer. A polyimide film and a laminate were obtained.

(Comparative Example 1)
In the same manner as in Example 1, except that a polyethylene terephthalate film with a release layer (Unipeel TR1, manufactured by Unitika Ltd., product name, thickness 38 μm) was used instead of the polyimide film with a release layer. A mold film and a laminate were obtained.

(Comparative Example 2)
Except that the release layer was not formed on the polyimide film, an adhesive layer was applied and formed on the polyimide film surface in the same manner as in Example 1 to obtain a release film with an adhesive layer and a laminate.

(Comparative Example 3)
Instead of the release polyimide film, an adhesive layer was applied and formed on the glossy surface of electrolytic copper foil (Furukawa Circuit Foil Co., Ltd., GTS-18, thickness 18 μm) to obtain a laminate as in Example 1. .

(Comparative Example 4)
A laminate was obtained in the same manner as in Example 1 except that a silicone release agent (manufactured by Shin-Etsu Chemical Co., Ltd., KS-774, trade name) was used in place of the resin varnish A for the release layer.

About the laminated board produced as described above, the surface roughness of the insulating layer (adhesive layer after thermosetting), non-migration, and the peelable laminated board after pressing, The surface flatness was measured as follows. The results are shown in Tables 1 and 2 below.

[Peelability after pressing]
After pressing, it was confirmed whether the release film could be peeled alone without deformation, fusion, or tearing. Further, when the release film was peeled from the laminated sample after pressing, it was visually confirmed whether or not the release film was peeled off at the interface with the release layer.
A: Easy peeling at the interface.
C: It cannot peel easily at the interface.
The phrase “cannot be easily peeled off at the interface” refers to the case where the film cannot be peeled alone, or the case where the resin composition of the adhesive layer is attached to the release film after peeling.

[Surface roughness]
The surface roughness of the insulating layer after pressing and peeling off the film was measured under the following measurement conditions using a surface shape measuring device (trade name: WykoNT9100, manufactured by Veeco).
-Measurement condition-
Internal lens: 1x External lens: 50x Measurement range: 0.125 x 0.095mm
Measurement depth: 10 μm
Measurement method: Vertical scanning type interference method (VSI method)

[Non-migration]
After peeling the polyimide film from the laminated sheet after pressing, Magic Ink (registered trademark) No. 1 manufactured by Teranishi Chemical Industry Co., Ltd. was formed on the insulating layer. 500 (black) was applied and the ink repellency was observed. Since the phenomenon of repelling ink indicates the transition of the release layer component to the insulating layer, the repellent one was evaluated as “C” and the non-repellent one as “A”.

[Surface flatness]
The surface shape of the insulating layer after pressing was observed using a high-precision three-dimensional surface shape roughness measurement system (Veeco, WYKO NT9100). 1 and 2 show the results of surface observation of the shape range of X axis: 125 μm and Y axis: 95 μm.

From Table 1, the characteristics of the release polyimide film of the present invention and the laminate with the adhesive layer can be easily peeled off after hot plate pressing at a high temperature of 240 ° C. as shown in Examples 1 to 5. An insulating layer having a flat surface could be obtained.
On the other hand, from Table 2, in Comparative Example 1 using a film other than a polyimide film, the polyethylene terephthalate film is fused to the end plate, the release film alone cannot be easily peeled off, and an insulating layer having a good surface state cannot be obtained. Was confirmed. Furthermore, in Comparative Example 2, it was confirmed that the polyimide film was torn and the polyimide film could not be peeled alone. In Comparative Example 3, the copper foil was broken, and it was confirmed that the copper foil alone could not be peeled off. In Comparative Example 4, when magic ink was applied to the insulating layer, ink repelling was observed, and it was confirmed that the release layer component was transferred to the insulating layer.
Moreover, although the observation result of the surface flatness of Example 1 is shown in FIG. 1 and the observation result of the surface flatness of Comparative Example 3 is shown in FIG. 2, when these are confirmed, the release polyimide film of the present invention in FIG. It was confirmed that the surface of the used insulating layer was flatter.

The release polyimide film of the present invention can be effectively used as a release film when a multilayer wiring board is produced by a molding method using a hot plate press, a roll laminator, a double press or the like.

Claims

A release polyimide film having a release layer containing an alkyd resin (A) and an amino resin (B) on at least one surface of the polyimide film.
2. The release polyimide film according to claim 1, wherein the release layer has a thickness of 0.01 to 10 μm.
The release polyimide film according to claim 1 or 2, wherein the polyimide film has a thickness of 10 to 100 µm.
The release polyimide film according to any one of claims 1 to 3, wherein a surface roughness (Ra) of a surface of the polyimide film on which the release layer is formed is 0.2 μm or less.
The release polyimide film according to any one of claims 1 to 4, further comprising an adhesive layer on a surface of the release layer on which no polyimide film is provided.
The mold release polyimide film according to claim 5, wherein the adhesive layer is made of a resin composition containing an epoxy resin and an epoxy resin curing agent.
A laminate with a release polyimide film with an adhesive layer, wherein the adhesive layer side of the release polyimide film according to claim 5 or 6 is laminated on at least one surface of a prepreg or an insulating layer.
A laminate obtained by peeling off the release polyimide film of the laminate according to claim 7.
A single layer or a multilayer in which the adhesive layer side of the release polyimide film according to claim 5 or 6 is laminated on one surface of a prepreg or an insulating layer, and the other surface of the prepreg or the insulating layer is processed into a circuit. A single or multilayer wiring board with a release polyimide film with an adhesive layer, which is laminated on the wiring board.
A process for producing a single layer or a multilayer wiring board with a release polyimide film with an adhesive layer by laminating the release polyimide film according to claim 5 or 6 on a single layer or a multilayer wiring board; The manufacturing method of a multilayer wiring board including the process of removing a mold release polyimide film from a single layer with a mold polyimide film, or a multilayer wiring board, and the process of circuit processing.