JP2003149803A - Photosensitive dry film resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is difficult to correct positioning of a conventional photosensitive film when the film is stuck to a CCL with a formed circuit after peeling a protective film because the photosensitive film is adhesive. SOLUTION: It is easy to correct positioning of a photosensitive film having no adhesion at room temperature even when the film is located on a substrate with a formed circuit and work efficiency is enhanced. A photosensitive dry film resist processable at a relatively low temperature, developable with an aqueous alkali solution and giving a film which satisfies the flame retardance standard UL94V-0 after curing is provided by using a photosensitive resin composition comprising (A) a soluble polyimide, (B) a compound to which one or more of phosphorus and halogen atoms or a siloxane moiety bonds covalently and (C) a (meth)acrylic compound as essential components as the material of a photosensitive film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photosensitive dry film resist, and more particularly to a photosensitive coverlay film for flexible printed wiring boards. Here, the photosensitive dry film resist is roughly classified into a film-like photoresist that is eventually peeled off after playing a role of an etching resist for forming a copper circuit, and a circuit of a circuit such as a printed wiring board. There are two types of photosensitive coverlay films that serve the dual roles of an insulating protective film and a film-like photoresist, and the present invention belongs to the latter. The present invention is a photosensitive coverlay film used for a head portion of a flexible printed wiring board or a hard disk device of a personal computer,
The present invention relates to a photosensitive dry film resist having a support film and a protective film which are excellent in releasability.

[0002]

2. Description of the Related Art Among photosensitive dry film resists, cover lay films, particularly cover lays for flexible printed wiring boards, are circuit protections for conductor circuit patterns of flexible printed wiring boards formed by using copper-clad laminates (CCL). Alternatively, it is used for the purpose of improving bending characteristics. As this cover lay film, conventionally, a method in which a cover film made of a polyimide film or the like with an adhesive on one side is perforated at a predetermined position and laminated on the CCL on which a circuit is formed by heat lamination or pressing is used. It is common. However, as the wiring of printed wiring boards is becoming finer, the method of aligning the circuit on the CCL after making holes or windows in the cover film at the terminals of the circuit or at the joints with parts is There is a limit in terms of position accuracy, and there is a problem that the yield is poor.

Further, after a cover film made of a polyimide film or the like having an adhesive on one surface is thermocompression-bonded on the CCL on which a circuit is formed, a hole is formed only in the cover film at a predetermined position by a method such as laser etching or plasma etching. Although there is also a method of opening the hole, it has a drawback in that although the positional accuracy is very good, it takes a long time to make a hole and the cost of the device and the operation are high. In order to solve these problems, there is a method of using a photosensitive resin composition as a cover lay film, particularly a photosensitive cover lay film. The present invention relates to the latter, and in this method, a photosensitive resin composition is applied onto a CCL on which a circuit is formed to form a photosensitive coverlay layer, or a photosensitive coverlay film is formed on the CCL on which a circuit is formed. By thermocompression-bonding on top, exposing a photomask pattern on it, exposing the base film, and performing alkali development, holes can be accurately formed at predetermined positions. If necessary, it is heat-cured to obtain a coverlay film. The photosensitive coverlay film is usually in a state in which a support film and a protective film are laminated, and the protective film is peeled off and then laminated on a substrate or the like. At this time, it is preferable that the photosensitive coverlay film is in a free-flowing state without tackiness at room temperature, and the resin can be fluidized to embed the circuit only at the time of thermal lamination. If a photosensitive cover lay film that is tacky at room temperature is used, it is difficult to correct the position because the CCL on which the circuit is formed is roughly aligned. Further, when the photosensitive cover lay film is peeled off for the purpose of correcting the position, an unreasonable force is applied, which may cause wrinkles on the substrate or the cover lay film. Further, even if the cover layer can be peeled off, a part of the cover lay remains on the copper foil, which cannot be reused and wasted.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to put into practical use a photosensitive dry film resist which has no tackiness at room temperature and has fluidity during thermocompression bonding. More specifically, the present invention relates to a photosensitive dry film resist, which has no tackiness at room temperature and can be easily position-corrected even if a photosensitive coverlay is placed on a substrate on which a circuit is formed.

[0005]

The object of the present invention is as follows.
This is achieved by adopting the following configuration. 1) A photosensitive dry film resist in a B stage state, a substrate temperature of 20 ° C. and a roll temperature of 2 on a glossy surface of a copper foil.
A photosensitive dry film resist, which can be peeled off without sticking to a copper foil even when laminated at 0 ° C. and a pressure of 1500 Pa · m. 2) The photosensitive dry film resist as described in 1), wherein the temperature at which the PI film in the B stage state and the glossy surface of the copper foil can be pressure-bonded is 50 ° C to 150 ° C. 3) A two-layer structure sheet formed by laminating a support film and a photosensitive film, wherein the peel strength between the support film and the photosensitive film is 0.5 Pa · m or more and 200 Pa.
-The photosensitive dry film resist according to 1) or 2), which is m or less. 4) A three-layer structure sheet obtained by laminating a support film, a photosensitive film and a protective film in this order, wherein the peel strength between the support film and the photosensitive film is 0.5 Pa.
The photosensitive dry film resist according to 1) or 2), wherein the photosensitive dry film resist has a thickness of not less than m and not more than 200 Pa · m. 5) A three-layer structure sheet obtained by laminating a support film, a photosensitive film, and a protective film in this order, wherein the peel strength between the protective film and the photosensitive film is 0.1 Pa · m or more in an environment where the temperature is 20 ° C. And 100 Pa · m or less, the photosensitive dry film resist according to any one of 1), 2) or 4). 6) The peel strength between the support film and the photosensitive film is
1) or 2), which is 1.2 times or more and 5 times or less the peel strength between the protective film and the photosensitive film,
Alternatively, a photosensitive dry film resist comprising the three-layer structure sheet according to any one of 3) to 5). 7) The photosensitive dry film resist according to any one of 1) to 6), wherein the photosensitive film contains polyimide. 8) The photosensitive film is (A) soluble polyimide,
(B) A photosensitive film comprising a photosensitive resin composition containing a (meth) acrylic compound containing at least one carbon-carbon double bond as an essential component, 1) to 7)
The photosensitive dry film resist according to any one of items. 9) A photosensitive film comprising a photosensitive resin composition containing (C) a compound containing a phosphorus and / or halogen and / or a siloxane moiety as an essential component in addition to the components (A) and (B). The photosensitive dry film resist according to any one of 1) to 8). 10) 30 to 70% by weight of the component (A), 5 to 50% by weight of the component (B), and 1% of the component (C) based on the total amount of the components (A), (B) and (C). The photosensitive dry film resist according to any one of 1) to 9), which is a photosensitive film produced from a photosensitive resin composition containing 50 to 50% by weight. 11) The photosensitive resin composition according to claim 9 or 10, which further comprises (D) a photoreaction initiator and / or a sensitizing dye in addition to the components (A), (B) and (C). A photosensitive dry film resist, which is a photosensitive film produced. 12) The photosensitive dry film resist according to any one of 1) to 11), wherein the photosensitive film has a thickness of 5 to 75 μm. 13) The photosensitive dry film resist according to any one of 1) to 12), wherein the support film has a thickness of 5 to 50 μm. 14) The photosensitive dry film resist according to any one of 1) or 2), or 4) to 13), wherein the protective film has a thickness of 5 to 50 μm. 15) A flexible printed wiring board using the photosensitive dry film resist according to any one of 1) to 14) as a cover lay. 16) A head for a hard disk drive of a personal computer, which uses the photosensitive dry film resist according to any one of 1) to 15) as a cover lay. 17) (A) according to any one of 8) to 11) above,
A method for producing a photosensitive film comprising a two-layer structure sheet, which comprises a step of applying an organic solvent solution of a photosensitive resin composition containing the component (B) onto a support film and drying the solution. 18) A method for producing a photosensitive film, which comprises a step of laminating a protective film on the photosensitive film comprising the two-layer structure sheet described in 17) above.

In the photosensitive dry film resist of the present invention, since the photosensitive film layer does not have adhesiveness to the copper foil or the PI film at room temperature, it is easy to correct the position of the photosensitive film on the circuit of the substrate, There is no wrinkling of the photosensitive film or damage to the substrate when trying to peel it off for correction.

Further, it has appropriate adhesion to the protective film and releasability at room temperature, and the peel strength of the support film from the photosensitive film is better than the peel strength of the protective film from the photosensitive film. If it is made larger, the protective film can be selectively peeled off, so that workability is further improved. The photosensitive film dry resist of the present invention is obtained by uniformly coating an organic solvent solution of a photosensitive resin on a support film and drying it, and then applying a protective film 10
A method of laminating at a temperature of -50 ° C is common.
If it is stored in the state of the two-layer structure sheet before laminating the protective film, it may be stored in a roll shape so that the surface of the photosensitive film is not dried or exposed to oxygen. In addition, if it is in the state of a three-layer structure sheet by laminating a protective film, it may be wound into a roll and stored,
Sheets may be cut into a suitable size and stored in a stacked state. In addition to the problem that dust is likely to adhere to the photosensitive film when it is exposed to air for a long time, the storage stability of the photosensitive film is extremely reduced by oxygen and moisture in the air, so it is stored in the state of a double-layered sheet. Rather than doing so, it is preferable to stack a protective film and store it in the state of a three-layer structure sheet. As the material of the support film, various commercially available films such as polyethylene terephthalate (PET) film, polyphenylene sulfide film, and polyimide film can be used, but the material is not limited to these. A PET film is often used as a support film because it has a certain degree of heat resistance and is relatively inexpensive to obtain. The peel strength between the surface of the support film bonded to the photosensitive film and the photosensitive film is preferably 0.5 Pa · m or more and 200 Pa · m or less. Peel strength between the support film and the photosensitive film is 0.5 Pa
If it is less than m, the adhesion of the photosensitive film to the support film tends to be poor. Further, if it is more than 200 Pa · m, the releasability is poor, so that an unreasonable force may be applied at the time of peeling and the photosensitive film may be broken or wrinkled. The surface of the support film bonded to the photosensitive film may be surface-treated in order to improve the adhesiveness and releasability, and an appropriate support film is selected depending on the photosensitive film. The peel strength can be measured as follows. First, a sample in which a support film and a photosensitive film are laminated is 2 cm.
It is cut into a width and a length of 7 cm, and the photosensitive film side is attached to a support such as an aluminum plate (thickness 3 mm) with a double-sided tape. A tensilon is used to pull the support film at 90 ° and measure the force required for peeling. A value obtained by dividing the measured value by 2 (width of sample: cm) is the peel strength (unit: Pa · m) as it is. The thickness of the support film is preferably 5 μm or more and 50 μm or less. More preferably, it is 10 μm or more and 30 μm or less. If the thickness is too small, wrinkles are likely to occur and the operability tends to be poor, and if the thickness is too large, the total weight becomes too heavy when a long sheet of photosensitive dry film resist is produced. Further, a protective film may be further laminated on the photosensitive film of the laminate (two-layer structure) of "support film / photosensitive film" to obtain a photosensitive dry film resist having a three-layer structure. The protective film is 10 on the surface of the photosensitive film.
It is preferable to laminate by laminating at a temperature of 50 ° C to 50 ° C. If the temperature is applied unnecessarily, the protective film expands due to thermal expansion, which causes wrinkles or curling after lamination.

Since the protective film is peeled off during use,
It is preferable that the joint surface between the protective film and the photosensitive film has appropriate adhesiveness during storage and, at the same time, has easy peelability. The peel strength between the protective film and the photosensitive film is 0.1 Pa · m or more and 100 Pa · m
It is preferably m or less. When the peel strength between the protective film and the photosensitive film is less than 0.1 Pa · m, the adhesion of the protective film to the photosensitive film is poor and air tends to enter easily. On the other hand, if it is larger than 100 Pa · m, it may take time and effort to peel the protective film from the photosensitive film. This peel strength measurement is
It can be measured as follows. First, the support film /
A sample in which a photosensitive film / protective film is laminated in this order is cut into a size of 2 cm width and 7 cm length,
The support film side is attached with a double-sided tape onto a support such as an aluminum plate (thickness: 3 mm). The force required when peeling by pulling only the protective film at 90 ° using Tensilon is measured. Measured value is 2 (width of sample:
Peel strength (unit: Pa · m)
Becomes

At this time, the peel strength between the protective film and the photosensitive film is preferably 1.2 times or more and 5 times or less the peel strength between the support film and the photosensitive film.
By doing so, it becomes possible to selectively peel the protective film from the photosensitive film. The releasability varies depending on the material of the photosensitive film, but can be controlled to some extent by selecting the material of the protective film and the surface-treated film.

The material of the protective film is a polyethylene film (PE film), a polyethylene vinyl alcohol film (EVA film), a "polyethylene / ethylene vinyl alcohol copolymer film" ((hereinafter abbreviated as (PE + EVA) copolymer film). ), "PE
"Laminate of film and (PE + EVA) copolymer film" or "film formed by simultaneous extrusion process of (PE + EVA) copolymer and polyethylene" (PE film surface on one side and (PE + EVA) copolymer weight on the other side) It becomes a film which is a united film surface) and the like, but is not limited thereto. The PE film has the advantages of being inexpensive and having a good surface slipperiness.
Further, the (PE + EVA) copolymer film has appropriate adhesion and releasability to the photosensitive film at the same time, but has a characteristic that the surface slipperiness is not so good.

Therefore, "PE film and (PE + EV
A) Copolymer film laminate "or" (P
"E + EVA) copolymer and polyethylene film produced by the simultaneous extrusion method" is used as a protective film so that the (PE + EVA) copolymer film surface is in contact with the surface to be joined with the photosensitive film, and contact with the support film is made. A method is preferred in which the PE film surface is on the side to be covered.

The use of this protective film improves the slipperiness of the surface of the three-layer structure sheet when the three-layer structure sheet consisting of the protective film / photosensitive film / support film is wound into a roll. There is. Further, the protective film may be provided with a light-shielding property, and as a method therefor, PE having a color that cuts light having a wavelength in a range absorbed by the photoinitiating reactant and the sensitizing dye contained in the photosensitive film is used. The method of coloring the film is taken.

Among the above protective films, "a laminated body of a PE film and a (PE + EVA) copolymer film"
For stretched polyethylene film (PE + EV
A) A copolymer film is laminated with an adhesive to produce it. Further, it is preferable that the surface of the copolymer film has been subjected to treatment for facilitating adhesion such as corona treatment. In case of laminating method, (PE + EVA) copolymer film and OPE
There are various methods for attaching the films, but a thin adhesive is coated on the OPE film,
After drying, the adhesive surface and the corona-treated surface of the (PE + EVA) copolymer film are generally laminated with a hot roll. The adhesive used for the above-mentioned bonding is not particularly limited, and an ordinary commercially available adhesive can be used, but a urethane-based adhesive is particularly effectively used.

Further, regarding the "film produced by the simultaneous extrusion process of (PE + EVA) copolymer and polyethylene", the amount of the resin comprising the copolymer of polyethylene and ethylene vinyl alcohol resin and the polyethylene resin at the time of simultaneous extrusion The thickness of each of the (PE + EVA) copolymer film and the PE film of the produced film can be controlled by adjusting the amount of With this method, one side is the PE film side and the other side is (PE + EV
A) A film having a copolymer film surface is obtained.

The (PE + EVA) copolymer film preferably contains no additives such as a lubricant and an antistatic agent. Since the (PE + EVA) copolymer film is in direct contact with the surface of the photosensitive film, when these additives bleed out from the protective film and are transferred to the photosensitive film, the adhesion and adhesiveness between the photosensitive film and CCL May decrease. Therefore, when using an additive to the protective film or performing surface treatment,
It is necessary to give due consideration to these points. Here, the thickness of the protective film is preferably 5 μm or more and 50 μm or less. More preferably, it is 10 μm or more and 30 μm or less. If the thickness is too small, it tends to wrinkle and tends to peel off, and if the thickness is too large, there is a problem that the total weight becomes too heavy when a long sheet-shaped photosensitive dry film resist is produced. . The thickness of the photosensitive film is preferably 5 μm or more and 75 μm or less. More preferably 10 μm or more and 60 μm
Hereafter, it is most preferably 15 μm or more and 40 μm or less. If the thickness of the photosensitive film is too small, the unevenness between the copper circuit such as a printed wiring board and the base film cannot be embedded, and the flatness of the surface is maintained after the CCL on which the circuit is formed and the photosensitive film are laminated. Since it is not possible, there is a tendency that problems such as poor flexibility are generated. On the other hand, if the thickness is too large, it tends to be difficult to develop a fine pattern, the resolution is lowered, and the sample after curing tends to warp. Furthermore, the photosensitive film preferably has appropriate adhesion and releasability to the protective film and the support film, and at the same time, from the viewpoint of workability, it is preferable that the photosensitive film does not have tackiness at room temperature,
It is preferable that the surface of the photosensitive film in the B stage state does not adhere to the copper circuit or the polyimide film to be bonded by lightly contacting it at room temperature. If there is tackiness (stickiness), if the film sticks while it is not flat, for example, when trying to peel off the photosensitive film for correction, excessive force is applied to damage the circuit of the board, The photosensitive film stretches. Next, the photosensitive resin composition used as the material for the photosensitive film layer will be described. The base polymer has a weight average molecular weight of 10,000 to 300,000, preferably 10,
000 to 150,000, more preferably 30,000
Polymers containing carboxyl groups in the range of 100,000 are preferred. Examples include, but are not limited to: Examples of the carboxyl group-containing polymer include acrylic copolymers containing (meth) acrylate as a main component and an ethylenically unsaturated carboxylic acid copolymerized therewith, but other copolymers may be used as necessary. It is also possible to use an acrylic copolymer obtained by copolymerizing monomers. The content of each component in this case is 15 to 85% by weight of the (meth) acrylate component, preferably 30 to 80% by weight, and 15 to 85% by weight of the ethylenically unsaturated carboxylic acid component, preferably 20 to 70% by weight. ,
The other copolymerizable monomer component is 0 to 15% by weight. Here, as the (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) ) Acrylate, benzyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate and the like. As the ethylenically unsaturated carboxylic acid to be reacted with this, for example, acrylic acid, methacrylic acid, monocarboxylic acids such as crotonic acid are preferably used, in addition, maleic acid, fumaric acid, dicarboxylic acids such as itaconic acid,
Alternatively, their anhydrides and half esters can also be used. Among these, acrylic acid and methacrylic acid are particularly preferable. Other copolymerizable monomers include
For example, tetrahydrofurfuryl (meth) acrylate,
(Meth) acryl dimethylaminoethyl ester, diethylaminoethyl (meth) acrylate, glycidyl methacrylate, 2,2,2-trifluoroethyl (meth) acrylate, (meth) acrylamide, 2,2
3,3-tetrafluoropropyl (meth) acrylate acrylamide, diacetone acrylamide, styrene, α-methylstyrene, vinyltoluene, vinyl acetate, alkyl vinyl ether, (meth) acrylonitrile and the like can be mentioned. In addition to the above, a polyester resin, a polyamide resin, a polyimide resin, a polyurethane resin, an epoxy resin or the like can be used in combination with the carboxyl group-containing polymer thus obtained. The weight average molecular weight of the carboxyl group-containing polymer is 10,0.
00 to 300,000, preferably 10,000 to 15
30,000, more preferably 30,000 to 100,0
It is preferably in the range of 00, and when the molecular weight is small, the film-forming ability is inferior. The carboxyl group-containing polymer may be a soluble polyimide described below. By using a photosensitive dry film resist that uses soluble polyimide as the component (A), a flexible printed wiring board coated with this as a cover lay film is flame-retardant so as to satisfy the UL94V-0 flame retardancy test standard for plastic materials. And self-extinguishing properties, heat resistance, excellent mechanical properties, good electrical insulation,
It is possible to impart alkali resistance. The soluble polyimide means 100 g of tetrahydrofuran at 20 ° C.
In 1.0, it means that it dissolves by 1.0 g or more.

The soluble polyimide is produced, for example, by the following production method. The soluble polyimide used in the present invention can be obtained from its precursor polyamic acid, which is obtained by reacting a diamine and an acid dianhydride in an organic solvent. In an inert atmosphere such as argon or nitrogen, diamine is dissolved in an organic solvent or dispersed in a slurry, and dianhydride is dissolved in an organic solvent, added in a slurry or added in a solid state. To do.

In this case, if the diamine and the acid dianhydride are substantially equimolar, a polyamic acid having one acid component and one diamine component can be obtained, but two or more acid dianhydride components and two or more diamine components are used. Can be used to adjust the molar ratio of the total amount of the diamine component and the total amount of the acid dianhydride component to be substantially equimolar to obtain the polyamic acid copolymer arbitrarily. For example, the diamine component-1 and the diamine component-2 may be added to the organic polar solvent first, and then the acid dianhydride component may be added to form a solution of the polyamic acid polymer. Alternatively, the diamine component-1 may be added in advance to the organic polar solvent, the acid dianhydride component may be added, the mixture may be stirred for a while, and the diamine component-2 may be added to form a solution of the polyamic acid polymer. Alternatively, the acid dianhydride component is first added to the organic polar solvent, the diamine component-1 is added, the mixture is stirred for a while, the diamine component-2 is added, the mixture is further stirred for a while, and the diamine component-3 is added. Alternatively, a solution of a polyamic acid polymer may be used.

The reaction temperature at this time is preferably -20 ° C to 90 ° C. The reaction time is about 30 minutes to 24 hours.

The average molecular weight of the polyamic acid is 50.
It is desirable that it is 00 to 1,000,000. When the average molecular weight is less than 5,000, the molecular weight of the finished polyimide composition also becomes low, and the resin tends to become brittle even if the polyimide composition is used as it is. On the other hand, 10,000
If it exceeds 00, the viscosity of the polyamic acid varnish tends to be high, which may make the handling difficult.

It is also possible to compound various organic additives or inorganic fillers or various reinforcing materials with this polyimide resin.

Examples of the organic polar solvent used in the polyamic acid-forming reaction include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide,
Formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, acetamide solvents such as N, N-dimethylacetamide and N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-
Pyrrolidone solvents such as vinyl-2-pyrrolidone, phenol, o-, m-, or p-cresol, xylenol, halogenated phenols, phenolic solvents such as catechol, tetrahydrofuran, dioxane, ether solvents such as dioxolane, methanol, ethanol,
Alcohol solvent such as butanol, cellosolve such as butyl cellosolve or hexamethylphosphoramide,
γ-butyrolactone and the like can be mentioned, and it is desirable to use these alone or as a mixture, but aromatic hydrocarbons such as xylene and toluene can also be used. The solvent is not particularly limited as long as it dissolves the polyamic acid. In a preferred method for producing a polyimide described below, a polyamic acid is synthesized, and then a solution of this polyamic acid is heated under reduced pressure to remove the solvent and perform imidization at the same time. It is advantageous in the process to select a low one.

Next, the step of imidizing the polyamic acid will be described.

When the polyamic acid is imidized, water is produced. The generated water easily hydrolyzes the polyamic acid and causes a decrease in the molecular weight. As a method for imidizing while removing this water, 1) a method of removing azeotropically by adding an azeotropic solvent such as toluene / xylene, 2) an aliphatic acid dianhydride such as acetic anhydride and triethylamine / pyridine / picoline / There is a chemical imidization method in which a tertiary amine such as isoquinoline is added, and 3) a method in which heat imidization is performed under reduced pressure. Either method may be used, but the method of 3) is preferable because the water generated by imidization is heated under reduced pressure and actively removed to the outside of the system to suppress hydrolysis and avoid a decrease in molecular weight. Most desirable. In the method 3), the acid dianhydride used as the raw material is mixed with a tetracarboxylic acid ring-opened by hydrolysis or a hydrolyzed one of the acid dianhydrides, resulting in a polyamic acid polymerization reaction. Even when the low molecular weight polyamic acid is stopped, by heating under reduced pressure during the subsequent imidization, the ring-opened acid dianhydride is closed again to become an acid dianhydride, and during imidization, It can be expected that the molecular weight of the polyimide becomes larger than the molecular weight of the polyamic acid before the imidization reaction by reacting with the amine remaining inside.

A specific method of heating and drying the polyamic acid solution under reduced pressure to directly imidize will be described.

Any method may be used as long as it can be dried by heating under reduced pressure, but it can be carried out as a batch method, a vacuum oven, or a continuous method, for example, by an extruder equipped with a decompression device. The extruder is preferably a twin-screw or three-screw extruder. These methods are selected according to the production volume. As used herein, the term "extruder with a decompressor" refers to a typical extruder that performs heating and melt extrusion of a thermoplastic resin.
It is a device in which a device for depressurizing and removing a solvent is attached to a twin-screw or three-screw melt extruder, which can be attached to a conventional melt extruder, or to create a device newly incorporating a decompression function. You can also With this apparatus, while the polyamic acid solution is kneaded by the extruder, the polyamic acid is imidized, the solvent and the water generated during the imidization are removed, and finally the generated soluble polyimide remains.

The heating conditions for imidization are 80 to 400.degree. The temperature is 100 ° C. or higher, preferably 120 ° C. or higher, at which imidization is efficiently performed and water is efficiently removed. It is desirable to set the maximum temperature to a temperature not higher than the thermal decomposition temperature of the polyimide to be used, and normally, the imidization is almost completed at about 250 to 350 ° C., so the maximum temperature can be set to this level.

It is preferable that the pressure is reduced so that the pressure is low, but the pressure may be such that water generated during imidization is efficiently removed under the above heating conditions. In particular,
Pressure for heating under reduced pressure is 0.09MPa-0.0001MP
a, preferably 0.08 MPa to 0.0001
MPa, more preferably 0.07 MPa to 0.00
It is 01 MPa.

The acid dianhydride used in this polyimide is not particularly limited as long as it is an acid dianhydride, but an acid dianhydride having 1 to 4 aromatic rings or an alicyclic acid dianhydride is used. Are preferable from the viewpoint of heat resistance.

These tetracarboxylic dianhydrides can be used alone or in combination of two or more.
Examples of the carboxylic acid dianhydride include butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and 1,3-dimethyl-1,2,3,4.
-Cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-
Tricarboxycyclopentyl acetic acid dianhydride, 3,5
6-tricarboxynorbonane-2-acetic acid dianhydride,
2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2 , 2, 2] -Oct-
Aliphatic or alicyclic tetracarboxylic dianhydrides such as 7-ene-2,3,5,6-tetracarboxylic dianhydride; pyromellitic dianhydride, 3,3 ', 4,4'- Benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'
-Biphenyl sulfone tetracarboxylic acid dianhydride, 1,
4,5,8-naphthalenetetracarboxylic dianhydride,
2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylethertetracarboxylic dianhydride, 3,3', 4,4'-dimethyldiphenylsilanetetracarboxylic Acid dianhydride, 3,3 ′,
4,4′-Tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′,
4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene- Bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylether dianhydride, bis (triphenylphthalic acid) ) -4,4'-Diphenylmethane dianhydride and other aromatic tetracarboxylic dianhydrides; 1,
3,3a, 4,5,9b-Hexahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-
1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan- 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-
Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione,

[0030]

[Chemical 1] (In the formula, R ¹ represents a divalent organic group having an aromatic ring, and R ² and R ³ are the same or different and represent a hydrogen atom or an alkyl group.)

[0031]

[Chemical 2] (Wherein R ⁴ represents a divalent organic group having an aromatic ring, and R ⁵ and R ⁶ are the same or different and represent a hydrogen atom or an alkyl group.) A compound or the like having an aromatic ring Group tetracarboxylic acid dianhydride and the like can be mentioned.

Of these acid dianhydrides, one aromatic ring is used.
From the viewpoint of heat resistance, it is preferable to use an acid dianhydride having 4 to 4 or an alicyclic acid dianhydride. These tetracarboxylic dianhydrides can be used alone or in combination of two or more. In particular, in order to obtain a polyimide having high solubility in an organic solvent, the following group 1:

[0033]

[Chemical 3] (In the formula, R ⁷ is-, an ether group, a carboxyl group, -S
O ₂ — or a divalent organic group, and Z represents an ether group or an ester group. It is desirable to partially use an acid dianhydride having an aromatic ring as represented by the structure (1). More preferably, it is desirable to partially use an acid dianhydride having four aromatic rings.

Next, the diamine used for this polyimide is not particularly limited as long as it is a diamine.
It is preferable to use a diamine component having a hydroxyl group and / or a carboxyl group in the molecule as at least a part of all diamine components. As a result, the resulting polyimide can have a hydroxyl group side chain and / or a carboxyl group side chain, and the solubility of the resulting photosensitive resin composition in alkali can be increased. Therefore, the photosensitive dry film resist using this photosensitive resin composition can use an alkaline solution as a developing solution. Further, the hydroxyl side chain and / or the carboxyl side chain of the polyimide may be reacted with an epoxy resin or epoxy acrylate to introduce another reactive functional group into the polyimide.

The diamine used for this polyimide is
From the point that it is possible to balance heat resistance and solubility,
The following general formula (1):

[0036]

[Chemical 4] (In the formula, R ⁸ is-, -CO-, -O-, -C (CF ₃ ).
_{2 -, - C (CH 3} ) 2 -, - COO -, - SO 2 - a, R
⁹ is the same or different and is hydrogen, hydroxyl group, carboxyl group, halogen, methoxy group, C1-C5 alkyl group, a is 0, 1, 2, 3 and b and c are 0, 1,
2, 3, 4 are shown. It is preferable to use the diamine represented by the formula (1). In particular, when a diamine in which R ⁹ in the general formula (1) is a hydroxyl group or a carboxyl group is used, the solubility of the polyimide in an alkaline aqueous solution can be increased. These diamine compounds may be used alone or in combination of two or more.

The diamine represented by the above general formula (1) is preferably used in an amount of 5 to 95 mol% based on the total amount of the diamine from the viewpoint that the obtained polyimide has high solubility. More preferably, it is 10 to 70 mol% in all amines.

From the viewpoint that the elastic modulus of the film can be lowered, the following general formula (2):

[0039]

[Chemical 5] (R ¹⁰ represents a hydrocarbon group having 1 to 12 carbon atoms, a phenyl group or a methoxy group, d is an integer of 1 to 5, and e is 1 to 2
It is an integer of 0. It is preferable to use the silicon diamine represented by the formula (1).

The silicon diamine represented by the above general formula (2) is preferably used in an amount of 5 to 50 mol% in all diamines in order to reduce the elastic modulus of the film. If it is less than 5 mol%, the effect of addition is insufficient, and if it is more than 50 mol%, the film tends to be too soft and the elastic modulus too low, or the thermal expansion coefficient tends to be large. When a hydroxyl group and / or a carboxyl group is introduced into the soluble polyimide by polymerizing a diamine component containing a part of a diamine having a hydroxyl group and / or a carboxyl group and an acid dianhydride component, solubility in alkali Is preferred, and an alkaline solution can be used as a developer, which is preferable. The diamine having a hydroxyl group and / or a carboxyl group is not particularly limited as long as it has a hydroxyl group and / or a carboxyl group.

The diamine having a hydroxyl group and / or a carboxyl group is not particularly limited as long as it has a hydroxyl group and / or a carboxyl group. For example, diaminophenols such as 2,4-diaminophenol, Hydroxybiphenyl compounds such as 3,3′-diamino-4,4′-dihydroxybiphenyl and 4,4′-diamino-3,3′-dihydroxybiphenyl, 3,
3'-diamino-4,4'-dihydroxydiphenylmethane, 4,4'-diamino-3,3'-dihydroxydiphenylmethane, 2,2-bis [3-amino-4-hydroxyphenyl] propane, 2,2- Bis [3-amino-4-hydroxyphenyl] hexafluoropropane,
4,4'-Diamino-2,2 ', 5,5'-hydroxydiphenylalkanes such as tetrahydroxydiphenylmethane, 3,3'-diamino-4,4'-dihydroxydiphenyl ether, 4,4'-diamino-3 , 3'-
Hydroxydiphenyl ether compounds such as dihydroxydiphenyl ether and 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenyl ether, 3,
3'-diamino-4,4'-dihydroxydiphenyl sulfone, 4,4'-diamino-2,2 ', 5,5'-
Diphenyl sulfone compounds such as tetrahydroxydiphenyl sulfone, 2,2-bis [4- (4-amino-
Bis [(hydroxyphenyl) phenyl] alkane compounds such as 3-hydroxyphenoxy) phenyl] propane, bis (hydroxyphenoxy) biphenyl compounds such as 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl , 2-bis [4- (4-amino-3)
Bis [(hydroxyphenoxy) phenyl] sulfone compounds such as -hydroxyphenoxy) phenyl] sulfone, diaminobenzoic acids such as 3,5-diaminobenzoic acid, 3,3'-diamino-4,4'-dicarboxybiphenyl, 4 , 4'-diamino-3,3'-dicarboxybiphenyl, 4,4'-diamino-2,2'-dicarboxybiphenyl, 4,4'-diamino-2,2 ', 5
Carboxybiphenyl compounds such as 5'-tetracarboxybiphenyl, 3,3'-diamino-4,4'-dicarboxydiphenylmethane, 4,4'-diamino-3,
3'-dihydroxydiphenylmethane, 4,4'-diamino-2,2'-dihydroxydiphenylmethane,
2,2-bis [3-amino-4-carboxyphenyl] propane, 2,2-bis [4-amino-3-carboxyphenyl] propane, 2,2-bis [3-amino-4-carboxyphenyl] hexa Fluoropropane, 4,4'-
Carboxydiphenylalkanes such as carboxydiphenylmethane such as diamino-2,2 ′, 5,5′-tetracarboxydiphenylmethane, 3,3′-diamino-
4,4'-dicarboxydiphenyl ether, 4,4 '
-Diamino-3,3'-dicarboxydiphenyl ether, 4,4'-diamino-2,2'-dicarboxydiphenyl ether, 4,4'-diamino-2,2 ', 5
Carboxydiphenyl ether compounds such as 5'-tetracarboxydiphenyl ether, 3,3'-diamino-
4,4'-dicarboxydiphenyl sulfone, 4,
4'-diamino-3,3'-dicarboxydiphenyl sulfone, 4,4'-diamino-2,2'-dicarboxydiphenyl sulfone, 4,4'-diamino-2,
Diphenyl sulfone compounds such as 2 ′, 5,5′-tetracarboxydiphenyl sulfone, 2,2-bis [4
Bis [(carboxyphenyl) phenyl] alkane compounds such as-(4-amino-3-carboxyphenoxy) phenyl] propane, 4,4'-bis (4-amino-
Bis (hydroxyphenoxy) biphenyl compounds such as 3-hydroxyphenoxy) biphenyl, 2,2-bis [4
Examples thereof include bis [(carboxyphenoxy) phenyl] sulfone compounds such as-(4-amino-3-carboxyphenoxy) phenyl] sulfone. The above diamine is preferably used in an amount of 10 to 100 mol% based on all diamines.

In addition to the above diamines, the following diamines may be used together as the diamine component. It is not particularly limited as long as it is a diamine, but for example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminophenylethane, 4,4′-diaminophenyl ether, 4,4 '
-Diaminophenyl sulfide, 4,4'-diaminophenyl sulfone, 1,5-diaminonaphthalene, 3,
3-Dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1 , 3,3-Trimethylindane, 4,4 '
-Diaminobenzanilide, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5
'-Tetrachloro-4,4'-diaminobiphenyl,
Aromatic diamines such as 1,3′-bis (4-aminophenoxy) benzene; Aroma having two amino groups bonded to an aromatic ring such as diaminotetraphenylthiophene and a hetero atom other than the nitrogen atom of the amino group. Group diamines;
1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4
-Diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine) and other aliphatic diamines and alicyclic diamines;

[0043]

[Chemical 6] (In the formula, R ¹¹ is -O-, -COO-, -OCO-, -C.
A divalent organic group selected from ONH- and -CO- is shown, and R ¹² is a monovalent organic group having a steroid skeleton. The compound etc. which are represented by the mono-substituted phenylenediamine represented by these are mentioned. These diamine compounds may be used alone or in combination of two or more.

A soluble polyimide having a hydroxyl group and / or a carboxyl group obtained by reacting the above acid dianhydride with a diamine is represented by the following general formula (3):

[0045]

[Chemical 7] (Wherein, f and g are integers of 1 or more satisfying f + g> 1, R ¹³ is a tetravalent organic group, R ¹⁴ is a divalent organic group, R
¹⁵ is a trivalent organic group, and R ¹⁶ is partly having a structure such as a hydroxyl group or a carboxyl group. The hydroxyl group and / or the carboxyl group introduced into the polyimide are reacted as follows and used as a modified polyimide. Good.

In order to impart further reactivity and curability to the soluble polyimide obtained as described above, a compound having an epoxy group capable of reacting with a soluble polyimide having a hydroxyl group and / or a carboxyl group introduced thereinto is added. By reacting, various functional groups described below are introduced,
It can be a modified polyimide. The compound having an epoxy group referred to here further includes, as a photopolymerizable and / or thermopolymerizable functional group, an epoxy group, a carbon-carbon triple bond,
It is preferable to have two or more functional groups selected from carbon-carbon double bonds. By introducing such a photopolymerizable and / or thermopolymerizable functional group, good curability and adhesiveness can be imparted to the resulting composition.

A method for introducing a functional group into a soluble polyimide having a hydroxyl group and / or a carboxyl group will be described below. Specifically, the modified polyimide is represented by the following general formula (4):

[0048]

[Chemical 8] (Wherein, f and g are integers of 1 or more satisfying f + g> 1, R ¹³ is a tetravalent organic group, R ¹⁴ is a divalent organic group, R
¹⁵ is a trivalent organic group, R ¹⁷ is the following group (1):

[0049]

[Chemical 9] (Wherein R ¹⁸ is a monovalent organic group having at least one functional group selected from the group consisting of an epoxy group, a carbon-carbon triple bond, or a carbon-carbon double bond))
Is a polyimide having at least one structural unit represented by. The modified polyimide having a hydroxyl group or a carboxyl group is dissolved in an organic solvent and reacted with a compound having an epoxy group to obtain a modified polyimide. The compound having an epoxy group is preferably an epoxy resin having two or more epoxy groups, and a compound having two or more functional groups selected from a carbon-carbon triple bond and a carbon-carbon double bond in addition to the epoxy group.

The epoxy resin having two or more epoxy groups is not particularly limited as long as it has two or more epoxy groups in the molecule, but it can be exemplified as follows.
For example, bisphenol type epoxy resin such as Epicoat 828 (produced by Yuka Shell Co.), orthocresol novolac type epoxy resin such as 180S65 (produced by Yuka Shell Co., Ltd.), bisphenol A novolac type epoxy such as 157S70 (produced by Yuka Shell Co., Ltd.) Resin, 1032H60 (produced by Yuka Shell Co., Ltd.) and the like, trishydroxyphenylmethane novolac type epoxy resin, ESN375 and the like, naphthalene aralkyl novolac type epoxy resin, tetraphenylolethane 1031S (produced by Yuka Shell Co., Ltd.), YGD414
S (Toto Kasei), Trishydroxyphenylmethane EP
PN502H (Nippon Kayaku), special bisphenol VG3
101L (Mitsui Chemicals), special naphthol NC7000
(Nippon Kayaku), TETRAD-X, TETRAD-C
Examples thereof include glycidyl amine type resins (manufactured by Mitsubishi Gas Chemical Co., Inc.) and the like.

The compound having an epoxy group and a carbon-carbon double bond is not particularly limited as long as it has an epoxy group and a double bond in the same molecule, but allyl glycidyl ether.
Examples thereof include glycidyl acrylate, glycidyl methacrylate, glycidyl vinyl ether, and the like.

The compound having an epoxy group and a carbon-carbon triple bond is not particularly limited as long as it has an epoxy group and a triple bond in the same molecule. It can be illustrated.

The solvent used in the reaction is not particularly limited as long as it does not react with the epoxy group and dissolves the polyimide having a hydroxyl group and / or a carboxyl group. For example, tetrahydrofuran, ether solvents such as dioxane, alcohol solvents such as methanol, ethanol, butanol, cellosolves such as butyl cellosolve or hexamethylphosphoramide, γ-butyrolactone, xylene, aromatic hydrocarbons such as toluene. It can be used. These can be used alone or as a mixture. Since the solvent is removed later, it is advantageous in terms of the process to dissolve the thermoplastic polyimide having a hydroxyl group or a carboxy group and select one having a boiling point as low as possible. The reaction temperature is preferably 40 ° C. or higher and 130 ° C. or lower at which the epoxy group reacts with the hydroxyl group / carboxyl group. In particular, for a compound having an epoxy group and a double bond or an epoxy group and a triple bond, it is desirable to react at a temperature at which the double bond and the triple bond do not crosslink or polymerize due to heat. Specifically, 4
It is 0 ° C. or higher and 100 ° C. or lower, and more preferably 50 ° C. or higher and 80 ° C. or lower. The reaction time is about 1 hour to about 15 hours. In this way, a modified polyimide solution can be obtained. In order to improve the adhesiveness and developability with the copper foil, the modified polyimide solution is appropriately heat-cured with an epoxy resin, an acrylic resin, a cyanate ester resin, a bismaleimide resin, a bisallylnadiimide resin, a phenol resin, or the like. A resin or a thermoplastic resin such as polyester, polyamide, polyurethane, or polycarbonate may be mixed. Soluble polyimide prepared as above,
Or modified polyimide, that is, the component (A) is
30 based on the total amount of the components (A), (B) and (C)
It is preferable to use ˜70% by weight. When it is less than 30%, it is difficult to realize flame retardancy of the coverlay film after curing, and mechanical properties tend to be deteriorated. When it is more than 70%, developability of the coverlay film tends to be deteriorated.

Next, the component (B) will be described. There is no particular limitation as long as it is a compound having a carbon-carbon double bond,
Divinylbenzene, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tetramethylolpropane tetraacrylate , Tetraethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, tetra Methylol pro Pan tetramethacrylate, tetraethylene glycol dimethacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro-2
-Hydroxypropyl methacrylate, stearyl methacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxypolyethylene glycol acrylate, β-acryloyloxyethyl hydrogen succinate, lauryl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate Methacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,
6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy 1,3 dimethacryloxypropane, 2,2-bis [4- (metacryloxyethoxy)
Phenyl] propane, 2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 2,2-bis [4-
(Methacryloxy-polyethoxy) phenyl] propane,
Polyethylene glycol diacrylate, triallyl isocyanurate, glycidyl methacrylate, glycidyl allyl ether, 1,3,5-triacryloylhexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, triallyl citrate , Triallyl phosphate, diallylamine,
Preferred are, but not limited to, diallyldimethylsilane, diallyl disulfide, diallyl ether, zalyl sialate, diallyl isophthalate, diallyl terephthalate, and the like. In order to improve the crosslink density, it is particularly desirable to use a bifunctional or higher functional monomer. Further, as the component (B), a compound having one or more aromatic rings and / or hetero rings in one molecule imparts fluidity when thermocompression-bonded when used as a dry film, It is preferable in that high resolution can be imparted.

In particular, as the component (B),-(CHR
¹⁹ --CH ₂ --O)-is a repeating unit (provided that R ¹⁹ is
A compound having hydrogen, a methyl group, or an ethyl group) makes it easy for the monomer before curing to dissolve in the alkaline aqueous solution, so that the resin in the exposed area will cure and the resin in the unexposed area will dissolve immediately in the alkaline aqueous solution. Since it is removed, good resolution can be provided in a short time, which is preferable. Particularly, the repeating unit is 6 to 40
A structure having not more than one is preferable.

The component (B) is represented by the general formula (5):

[0057]

[Chemical 10] (However, in the formula, R ²⁰ is hydrogen or a methyl group, or an ethyl group, R ²¹ is a divalent organic group, and h and i are 2 to 2
It is preferably a di (meth) acrylate compound having two aromatic rings as represented by (integer up to 0).
When h and i are 0 or 1, the solubility of the composition in an alkaline aqueous solution is poor, and good developability tends to be lost, and materials having h and i of 21 or more are not available. If it is difficult, the solubility in an alkaline aqueous solution is good, but the produced film tends to easily absorb moisture. Further, the component (B) is a group (2):

[0058]

[Chemical 11] (However, in the formula, R ²² is a divalent organic group, and R ²³ is -or 2
A divalent compound having one or more aromatic rings, such as a valent organic group, j is an integer of 1 to 10 and k and m are integers of 1 to 10. When j, k and m are 11 or more, it is not preferable because it is difficult to obtain the material and the solubility in the alkaline aqueous solution is good, but the produced film tends to absorb moisture.

As the (meth) acrylic compound having one or more aromatic rings and / or heterocycles and one or more carbon-carbon double bonds in one molecule which is the component (B), the following may be mentioned. It can be illustrated.

For example, Aronix M-210, M-211B (manufactured by Toagosei), NK ester ABE-300, A-BPE-4, A-BPE-10,
A-BPE-20, A-BPE-30, BPE-100, BPE-200 (manufactured by Shin-Nakamura Chemical Co., Ltd.), bisphenol A EO-modified di (meth) acrylate, Aronix M-208 (manufactured by Toagosei), etc. Bisphenol A such as EO-modified (n = 2-20) di (meth) acrylate, Denacol acrylate DA-250 (Nagase Kasei), Viscoat # 540 (Osaka Organic Chemical Industry)
Phthalic acid PO such as PO-modified (n = 2-20) di (meth) acrylate, denacol acrylate DA-721 (manufactured by Nagase Kasei)
A modified diacrylate can be mentioned. further,
Isocyanuric acid such as Aronix M-215 (manufactured by Toagosei) or EO-modified diacrylate, Aronix M-315 (manufactured by Toagosei), NK ester A-9300 (manufactured by Shin-Nakamura Chemical), etc. It may contain an acrylate such as EO-modified triacrylate.

The component (B) is preferably blended in an amount of 1 to 50% by weight based on the total amount of the components (A), (B) and (C). If it is less than 1% by weight, the pressure-bonding temperature tends to be high and the resolution tends to be poor, and if it is more than 50% by weight, B
The film in the stage state is sticky, tends to adhere to the copper foil or the polyimide film even at room temperature, and the resin tends to exude during thermocompression bonding, and the film after curing tends to become brittle. Preferably 1-40% by weight
And more preferably 5 to 30% by weight. Next, the compound containing a phosphorus and / or halogen and / or a siloxane moiety as the component (C) will be described. By using these compounds, flame resistance and high solder heat resistance can be imparted to the photosensitive cover lay film after curing. When the component (C) is a phosphorus-containing compound, the phosphorus content is preferably 5.0% or more, and more preferably 7.0% or more, from the viewpoint of effectively imparting flame retardancy. . When the component (C) is a compound containing halogen, the halogen content is preferably 15% or more, and more preferably 20% or more from the viewpoint of effectively imparting flame retardancy. As the halogen, one using chlorine or bromine is generally used. When the component (C) is a compound containing a siloxane moiety, it is preferably an organopolysiloxane compound containing a high proportion of aromatic rings, because heat resistance and flame retardancy can be effectively imparted. When a phosphorus compound is used as the component (C), examples of the phosphorus compound include phosphine, phosphine oxide, phosphoric acid ester (including condensed phosphoric acid ester), and phosphorous compound such as phosphorous acid ester. A phosphine oxide or a phosphoric acid ester (including a condensed phosphoric acid ester) is preferable from the viewpoint of compatibility with the soluble polyimide which is the component A). The phosphorus content of the phosphorus compound used as the component (C) is preferably 5.0% by weight, more preferably 7.0% or more. Furthermore, from the viewpoint of imparting flame retardancy and excellent hydrolysis resistance, the group (3):

[0062]

[Chemical 12] (Wherein R ²⁴ is a methyl group, R ²⁵ is an alkyl group or a phenyl group, X is a divalent organic group, n is an integer from 0 to 3, p and q are 0 to 3 satisfying p + q = 3. integer)
A phosphoric acid ester represented by More preferably, it is a phosphoric acid ester having two or more aromatic rings. Since such a phosphoric acid ester compound dissolves in an alkaline aqueous solution, it can be developed with an alkaline aqueous solution when used as a material for a photosensitive coverlay. Examples of such phosphorus compounds include the following. For example, T
PP (triphenyl phosphate), TCP (tricresyl phosphate), TXP (tricylenyl phosphate), CDP (cresyl diphenyl phosphate),
PX-110 (cresyl 2,6-xylenyl phosphate)
(All manufactured by Daihachi Chemical Co., Ltd.)
733S (Resorcinol Diphosphate), CR-74
1, CR-747, PX-200) (all manufactured by Daihachi Chemical Co., Ltd.), non-halogenated condensed phosphoric acid ester, biscoat V3PA (manufactured by Osaka Organic Chemical Industry), and MR-260 (manufactured by Daihachi Chemical Industry) Examples thereof include acid (meth) acrylate and phosphite esters such as triphenyl phosphite. From the viewpoint of hydrolysis resistance, phosphorus compounds may be hydrolyzed under pressure and humidity conditions. Therefore, when a bromine-containing compound and a phosphorus compound are used together, both flame retardancy and hydrolysis resistance are obtained. It can be realized.
When a halogen-containing compound is used as the component (C), the halogen content is preferably 30% by weight or more, more preferably 40% by weight or more, and most preferably 50% or more. From the standpoint of improving flame retardancy, the higher the halogen content, the better. Also,
From the viewpoint of having a curable reactive group and simultaneously imparting heat resistance and flame retardancy, the following group (4):

[0063]

[Chemical 13] (In the formula, Y is a halogen group, R ²⁶ and R ²⁷ are hydrogen or a methyl group, r is an integer from 0 to 10, and s is 1
It is preferable to contain at least one kind of compound selected from (meth) acrylic compounds represented by an integer of 1 to 5 and t is an integer of 1 to 4). Examples of the halogen-containing compound include an organic compound containing chlorine and an organic compound containing bromine. From the viewpoint of imparting flame retardancy, a bromine-containing compound is preferable, and the group (4): Examples of the bromine-containing acrylic compound to be used include the following. For example, New Frontier BR-30, BR-30M, BR-31, BR
-42M (manufactured by Daiichi Kogyo Seiyaku) and the like, brominated aromatic triazine such as Pyrogard SR-245 (manufactured by Daiichi Kogyo Seiyaku), Pyrogard SR-250, SR-4
Examples thereof include brominated aromatic polymers such as 00A (Daiichi Kogyo Seiyaku) and brominated aromatic compounds such as Pyrogard SR-990A (Daiichi Kogyo Seiyaku). Also,
The component (C) may be a phosphorus compound having a halogen atom in one molecule, and such a compound is CL
P (tris (2-chloroethyl) phosphate), TMC
PP (tris (chloropropyl) phosphate), CR
P (tris (dichloropropyl) phosphate), CR
Examples thereof include halogen-containing phosphoric acid esters such as -900 (tris (tribromoneopentyl) phosphate) (all manufactured by Daihachi Chemical Co., Ltd.). When a halogen-containing compound is used as the component (C), when antimony trioxide and / or antimony pentoxide is added, the antimony oxide extracts halogen atoms from the flame retardant in the thermal decomposition initiation temperature range of the plastic. Since antimony halide is produced, flame retardancy can be synergistically increased. The addition amount thereof is preferably 0.1 to 10% by weight based on the total weight of the components (A), (B) and (C),
More preferably, it is 1 to 6% by weight.
Further, when a compound having a siloxane moiety is used as the component (C), it is preferably an organopolysiloxane compound containing a high proportion of aromatic rings because it imparts flame retardancy, and a phenyl group is used as a total organic substituent. Out of 1
It is preferable that the organopolysiloxane compound contains 0% or more, more preferably 20% or more, and more preferably 25% or more. The smaller the phenyl group content, the smaller the flame retardant effect, and the higher the phenyl group content, the higher the flame retardant effect, which is desirable. When an organopolysiloxane compound having a low phenyl group content is used as the component (C), the dispersibility or compatibility with the (A) soluble polyimide or (B) acrylic resin tends to be poor, and the photosensitive resin is used as a film. When it is made into a polymer, it tends to obtain only a low transparency film in which a plurality of components having different refractive indexes are phase-separated or an opaque film. Further, when such an organopolysiloxane compound having a low phenyl group content is used, it is difficult to obtain a sufficient flame retardant effect unless the addition amount is increased, but when the addition amount is increased, a photosensitive coverlay produced. The physical properties such as mechanical strength tend to decrease significantly. Examples of the organopolysiloxane compound containing a high proportion of aromatic rings include the following. For example, KF manufactured by Shin-Etsu Silicone Co., Ltd.
50-100S, KF54, KF56, HIVAC F
4, HIVAC F5, X-22-1824B, KR2
11, KR311 and the like, which may be used alone or in combination of two or more kinds. The component (C) is
5 based on the total amount of the components (A), (B) and (C)
It is preferable to use 50% by weight. When it is less than 5%, it tends to be difficult to impart flame retardancy to the cured coverlay film, and when it is more than 50%, mechanical properties of the cured coverlay film tend to be deteriorated.

Further, the composition of the present invention preferably contains a component (D) and a photoreaction initiator so that a desired pattern can be drawn by exposure and development. As examples of compounds that generate radicals by light having a long wavelength of about the g-line, the following general formulas (6) and (7):
Conversion 14,

[0065]

[Chemical 14] (In the formula, R ²⁸ , R ^29, and R ³⁰ are C ₆ H ₅ −, C ₆ H ₄ (C
_{H 3) -, C 6 H} 2 (CH 3) 3 -, (CH 3) 3 C-, C 6 H
₃ Cl ₂ —, R ³¹ , R ³² and R ³³ are C ₆ H ₅ —, methoxy group, ethoxy group, C ₆ H ₄ (CH ₃ ) —, C ₆ H ₂ (C
H ₃ ) ₃ −. ) And an acylphosphine oxide compound represented by the formula (1). The radical generated thereby reacts with a reactive group having a carbon-carbon double bond (vinyl, acroyl, methacroyl, allyl, etc.) to promote crosslinking / polymerization.

Whereas the acylphosphine oxide represented by the general formula (6) generates two radicals, the acylphosphine oxide represented by the general formula (7) particularly has four radicals by α cleavage. It is more preferable because it generates radicals.

In order to cure the epoxy group, the carbon-carbon double bond and the triple bond attached to the side chain of the polyimide resin,
A photo cation generator may be used in place of the above radical generator. For example, diphenyliodonium salts such as diphenyliodonium salt of dimethoxyanthraquinone sulfonic acid, triphenylsulfonium salts, pyrilinium salts, triphenylonium salts, diazonium salts and the like can be exemplified. At this time, it is preferable to mix an alicyclic epoxy or vinyl ether compound having high cation curability.

Alternatively, a photobase generator may be used to cure the epoxy group, carbon-carbon double bond or triple bond attached to the side chain. For example, a urethane compound obtained by the reaction of nitrobenzyl alcohol or dinitrobenzyl alcohol with an isocyanate, or a urethane compound obtained by the reaction of nitro-1-phenylethyl alcohol or dinitro-1-phenylethyl alcohol with an isocyanate, dimethoxy-2. Examples thereof include urethane compounds obtained by the reaction of phenyl-2-propanol and isocyanate.

It is desirable to add a sensitizer to the composition of the present invention in order to achieve a practically useful photosensitivity. Preferred examples of the sensitizer include Michlerketone, bis-4,4′-diethylaminobenzophenone, benzophenone, camphorquinone, benzyl, 4,4′-dimethylaminobenzyl, 3,5-bis (diethylaminobenzylidene) -N-methyl. -4-piperidone, 3,5-
Bis (dimethylaminobenzylidene) -N-methyl-4
-Piperidone, 3,5-bis (diethylaminobenzylidene) -N-ethyl-4-piperidone, 3,3'-carbonylbis (7-diethylamino) coumarin, 3- (2
-Benzothiazolyl) -7-diethylaminocoumarin,
2- (p-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) quinoline, 4
-(P-dimethylaminostyryl) quinoline, 2- (p
-Dimethylaminostyryl) benzothiazole, 2-
(P-Dimethylaminostyryl) -3,3-dimethyl-
Examples thereof include, but are not limited to, 3H-indole and the like.

Various peroxides can be used as a radical initiator in combination with the sensitizer. Particularly, a combination with 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone is particularly preferable.

The total weight of the photoreaction initiator and the sensitizer is preferably 0.001 to 10 parts by weight based on the total weight of the above-mentioned (A) component, (B) component and (C) component. It is more preferable that the amount is 0.01 to 10 parts by weight. If it deviates from the range of 0.001 to 10 parts by weight,
The sensitizing effect may not be obtained, or the developability may be adversely affected. As the photoreaction initiator and the sensitizer, one kind of compound may be used,
You may mix and use several types.

In producing a photosensitive dry film resist using the photosensitive resin composition of the present invention, first,
Component (A), component (B), component (C), and optionally component (D) are uniformly dissolved in an organic solvent. The organic solvent used here may be a solvent that dissolves the photosensitive resin composition, and examples thereof include ether solvents such as dioxolane, dioxane and tetrahydrofuran, ketone solvents such as acetone and methyl ethyl ketone, methyl alcohol and ethyl alcohol. An alcohol solvent or the like is used. These solvents may be used alone or in combination of two or more. Since the solvent is removed later, it is advantageous in the process to dissolve the components (A), (B), (C), and (D) and select one having a boiling point as low as possible. Then, the photosensitive resin composition in the form of a solution is uniformly applied onto the support film, and then the solvent is removed by heating and / or blowing with hot air, followed by drying to obtain a photosensitive dry film resist. The drying temperature at this time is
The temperature is preferably such that the curable group such as an acrylic group contained in the component (B) does not react, preferably 120 ° C. or lower, more preferably 100 ° C. or lower.
The drying time may be a time sufficient for the solvent to be removed, but a shorter time is advantageous in the process. Specifically, 1) a method of drying at a temperature of 80 to 120 ° C. for 2 minutes or more in a short time, and 2) 45 ° C. for 5 minutes and 65 ° C.
There is a method of drying by gradually increasing the temperature from a low temperature such as 5 minutes at 85 ° C. for 5 minutes. The method of drying at a relatively high temperature as described in 1) is suitable when the thickness of the photosensitive film is small, and can be dried in a short time, and is therefore advantageous when producing a long photosensitive film. However, if the photosensitive film thickness is as large as 50 μm or more,
It takes time for the solvent dissolving the photosensitive resin composition to be removed by evaporation, and even if the surface is dried by drying at a high temperature, the solvent still remains inside the film,
In the process of exuding the resin when laminating on a substrate, etc., or heat curing after laminating, pattern exposure and development,
There is a problem that the photosensitive film may foam. Therefore, when the thickness of the photosensitive film is relatively large, it takes a drying time, but a method of gradually increasing the drying temperature as in 2) is preferable. Further, if the drying is insufficient, tackiness (stickiness) is observed in the photosensitive film in the B stage state, and even if a protective film is laminated on the photosensitive film, a part of the photosensitive resin component is peeled off when the protective film is peeled off. The protective film surface may be adhered and transferred, or a part of the photosensitive resin component may be adhered and transferred to the support film surface when the support film is peeled off. Furthermore, the peeling strength from the protective film or the support film becomes too large, and the workability at the time of peeling decreases, or when the protective film or the support film is peeled off, too much force is applied to damage the circuit or substrate. To do. In addition, even if the protective film can be peeled off well, when the photosensitive film is placed on the CCL or film on which circuits are formed randomly, it sticks even at room temperature due to stickiness, and the position of the photosensitive film is corrected. Become difficult or try to peel CC
L or the photosensitive film may wrinkle.

The support film is preferably excellent in adhesion to the photosensitive dry film resist in the B stage state, and is surface-treated so that the support film is easily peeled off when the photocrosslinking reaction is initiated by exposure. Those that are preferable. The material and thickness of the support film and the peel strength between the support film and the photosensitive film are as described above. Usually, a photosensitive dry film resist is one in which the above-mentioned photosensitive composition is kept in a semi-cured state (B stage), has fluidity during hot pressing or laminating, and follows irregularities of a circuit of a flexible printed wiring board. It is designed so that curing is completed by photo-crosslinking reaction during exposure, heat during press working and heating cure performed after pressing. Further, a protective film is preferably laminated on the photosensitive dry film resist prepared by applying the photosensitive resin composition onto a support film and drying it. It is possible to prevent dust and dirt in the air from adhering, and prevent deterioration of quality due to drying of the photosensitive dry film resist.

The preferable material and thickness of the protective film and the peel strength between the support film and the photosensitive film are as described above. The protective film is laminated on the photosensitive dry film resist prepared on the support film at room temperature. When manufacturing a cover lay for a flexible printed wiring board using a photosensitive dry film resist comprising a three-layer structure sheet according to the present invention, after removing the protective film,
The flexible printed wiring board on which the circuit is formed and the photosensitive film are laminated by heating laminate. If the temperature during lamination is too high, the photosensitive reaction sites will be crosslinked and the film will be hardened, and the function as a photosensitive coverlay will be lost, so the temperature during lamination is preferably low. Specifically, the temperature is 60 ° C to 150 ° C, more preferably 80 ° C to 120 ° C. When the temperature is too low, the fluidity of the photosensitive dry film resist is deteriorated, so that it is difficult to cover a fine circuit on the flexible printed wiring board and the adhesion tends to be deteriorated.

In this way, the flexible printed wiring board / photosensitive film / support film are laminated in this order. The support film may be peeled off when the lamination is completed, or may be peeled off after the exposure is completed.
From the perspective of protecting the photosensitive dry film resist,
It is preferable to peel off the support film after applying a photomask pattern and exposing.

Further, this photosensitive dry film resist is a cover layer for curing the film by adhering it onto the circuit of the flexible printed wiring board, irradiating it with light such as ultraviolet rays, and then curing it by heating to cure the film. Becomes

Since the photoreaction initiator contained in the photosensitive dry film resist usually absorbs light having a wavelength of 450 nm or less, it is preferable to use a light source that effectively emits light having a wavelength of 300 to 430 nm as irradiation light. .

Further, when the photosensitive dry film resist of the present invention is used as a photosensitive cover lay for a flexible printed wiring board, it is adhered onto the circuit of the flexible printed wiring board, and then a photomask pattern is placed, exposed and developed. By doing so, it is possible to make a hole at a desired position.

As the developing solution, an aqueous solution having a basicity or an organic solvent can be used. The solvent for dissolving the basic compound may be water or an organic solvent. To improve the solubility of polyimide, methanol,
Ethanol, propanol, isopropyl alcohol,
It may further contain a water-soluble organic solvent such as isobutanol, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, or a mixture of two or more solvents. Good. Considering the effect on the environment, it is preferable not to use an organic solvent, and it is most preferable to use an alkaline aqueous solution as a developer. As the basic compound, one kind may be used, or two or more kinds may be used. May be. The concentration of the basic compound is usually 0.1 to 10% by weight, but it is preferably 0.1 to 5% by weight because of the influence on the film. Examples of the basic compound include alkali metal, alkaline earth metal or ammonium ion hydroxides or carbonates, amine compounds and the like.

The photosensitive dry film resist of the present invention comprises a soluble polyimide as the component (A), a (meth) acrylic compound having at least one carbon-carbon double bond as the component (B), and a phosphorus as the component (C). Alternatively, by preparing from a photosensitive resin composition containing a compound containing a halogen or siloxane moiety and a photoreaction initiator and / or a sensitizer as the component (D), the resin in the exposed area is cured and the resin in the unexposed area is cured. Since the resin is quickly dissolved and removed by the alkaline aqueous solution, it has a good resolution in a short time.

Further, by using the component (C): a compound containing a phosphorus, halogen or siloxane moiety as the flame retardant, the flame retardancy of the plastic material in the state of being laminated with the polyimide film on the cured photosensitive dry film resist. It is possible to impart flame retardancy and solder heat resistance satisfying the property test standard UL94V-0. Furthermore, by using polyimide as the main component, excellent electrical insulation,
Since it has heat resistance and mechanical properties, the photosensitive dry film resist of the present invention is suitable for a photosensitive coverlay for a flexible printed wiring board as well as a photosensitive coverlay for a head of a hard disk device of a personal computer. In particular, the photosensitive dry film resist of the present invention has good releasability of the protective film and the support film, so that the protective film can be easily peeled off at the time of use and the workability is improved. Since it is not necessary to apply excessive force when peeling, the cover lay and the substrate are not damaged.

[0082]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. Preparation of the photosensitive dry film resist and the three-layer structure sheet and evaluation of the photosensitive dry film resist in the examples were carried out as follows. (1) Preparation of photosensitive dry film resist After dissolving soluble polyimide (A) component in an organic solvent to a solid content of 30% by weight, (B) having one or more carbon-carbon double bonds (meth) An acrylic compound, (C) a compound containing phosphorus and / or halogen and / or siloxane moieties, and a photoreaction initiator as component (D) are mixed to prepare a varnish of the photosensitive resin composition.
The varnish of this photosensitive resin composition is used as a support film; PE
On the T film (thickness 25 μm), the thickness after drying is 25
It was applied so as to have a thickness of μm, dried at 65 ° C. for 10 minutes to remove the organic solvent, and was used as a photosensitive dry film resist having a two-layer structure in the B stage state. (2) Selection of protective film As a protective film, a commercially available Sanite Kaken Co., Ltd. manufactured Sanitect film (thickness 25 μm) consisting of “a laminated film of a PE film and a low-density olefin copolymer film”, and A commercially available Sekisui Chemical Co., Ltd. Protect (# 6221F) film (thickness 50 μm) was used as the “film formed by simultaneous extrusion production of (EVA + PE) copolymer and polyethylene”. (3) Lamination of protective film In the case of a sanitect film, the low-density olefin copolymer film surface is in contact with the photosensitive film surface.
EVA) A copolymer film was laminated so that the surface of the copolymer film was in contact with the surface of the photosensitive film to prepare a photosensitive dry film resist composed of a three-layer structure sheet. The laminating conditions were a roll temperature of 40 ° C. and a nip pressure of 1500 Pa · m. (4) Evaluation of three-layer structure sheet The obtained three-layer structure sheet and the photosensitive film were evaluated for various properties with respect to the following four items. <Adhesiveness of Photosensitive Film> The photosensitive film from which the protective film has been peeled off is laminated on the glossy surface of the copper foil at a substrate temperature of 20 ° C., a roll temperature of 20 ° C., and a pressure of 1500 Pa · m. Then, the photosensitive film was peeled off from the copper foil, and a part of the film did not remain on the copper foil, and if the copper foil could be peeled off without wrinkling, it was judged as passing. <Removability of protective film> A three-layer structure sheet cut into a size of 2 cm width and 7 cm length was attached to an aluminum plate (thickness 3 mm) using a double-sided tape, and then the peeling speed was 15
The protective film was pulled at 90 ° at a rate of cm / min and measured with a tensilon. A value obtained by dividing the measured value by 2 (width of sample: cm) is the peel strength (unit: Pa · m) as it is.

The peelability of the protective film is practically 0.1 to
100 Pa · m is preferable, and the range is regarded as acceptable. Further, when it was more than 100 Pa · m, the peeling was too heavy, so the test was rejected. <Support film peelability> A three-layer structure sheet cut into a size of 2 cm width and 7 cm length was attached to an aluminum plate (thickness 3 mm) using a double-sided tape, and then peeling speed 1
The support film was pulled 90 degrees at 5 cm / min and measured with Tensilon. Measured value is 2 (width of sample: cm)
The value obtained by dividing by is the peel strength (unit: Pa · m). Peelability of the support film is practically 0.5 to 200
Pa · m is preferable, and the range is regarded as acceptable. Again 200
If it was larger than Pa · m, the peeling was too heavy and the test was rejected. <Developability> After peeling off the protective film of the three-layer structure sheet, the photosensitive dry film resist surface is laminated on the glossy surface of the electrolytic copper foil 35 μm and shielded from light at 100 ° C. at 20000 Pa.
It was laminated with m. A mask pattern is placed on the support film of this laminate, and light with a wavelength of 400 nm is applied.
Exposure is performed at 00 mJ / cm ² . After peeling off the support film of this sample, a 1% aqueous solution of potassium hydroxide (liquid temperature 40 ° C.) and a spray pressure of 0.85 MPa were used using a spray developing machine (Etching Machine ES-655D manufactured by Sanhayato Co., Ltd.). Development was carried out under the condition that the exposure time to the developer was 2 minutes. The photomask pattern to be placed on the cover film before exposure is a pattern in which fine holes of 100 × 100 μm square are drawn. The pattern formed by development is then washed with distilled water to remove the developer and dry. If a 100 × 100 μm square hole was developed, it was determined to be acceptable.

[0084]

Example 1 As a raw material of polyimide, (2,2'-bis (4-
(Hydroxyphenyl) propanedibenzoate) -3,3 ', 4,
4'-tetracarboxylic acid anhydride (hereinafter referred to as ESDA), bis [4- (3-aminophenoxy) phenyl] sulfone (hereinafter referred to as BAPS-M), silicon diamine,
Diaminobenzoic acid and [bis (4-amino-3-carboxy) phenyl] methane (hereinafter referred to as MBAA) were used. N, N'-dimethylformamide (DMF) and dioxolane were used as the solvent. (Synthesis of polyimide resin) In a 500 ml separable flask equipped with a stirrer, ESDA 17.3 g (0.030 mol), DMF30 g
And dissolve with stirring with a stirrer. Next, 5.15 g (0.018 mol) of diamine MBAA manufactured by Wakayama Seika is dissolved in 9 g of DMF, and the mixture is vigorously stirred for 1 hour. Furthermore, silicon diamine KF-8010 (made by Shin-Etsu Silicone) 7.47 g (0.009
(mol) and stirred for about 1 hour. Finally, BAPS-M 1.
Add 29 g (0.003 mol) and stir vigorously for 1 hour. The polyamide solution thus obtained was placed in a vat coated with Teflon (R) and placed in a vacuum oven at 200 ° C. for 660
It was dried under reduced pressure at a pressure of Pa for 2 hours to obtain 26.40 g of soluble polyimide. 15 g of the polyimide thus synthesized was dissolved in 50 g of dioxolane to prepare a varnish with Sc = 30%. (Production of Photosensitive Dry Film Resist) The components (a) to (d) shown below are mixed to prepare a photosensitive resin composition, and the photosensitive dry film of B stage is formed on the PET film by the method (1). A resist was prepared. Sekisui Chemical Co., Ltd. on top of this two-layer photosensitive dry film resist
Protect (# 6221F) film (thickness 50μ
m) was laminated as a protective film to prepare a three-layer structure sheet. (A) 60 parts by weight of the polyimide resin synthesized by the above method (b) 20 parts by weight of bisphenol A EO-modified (m + n≈30) diacrylate (NK ester A-BPE-30 manufactured by Shin-Nakamura Chemical Co., Ltd.) c) TPP (triphenyl phosphate) 20 parts by weight (d) Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals KK Irgacure 819) 1 part by weight Adhesion of this photosensitive film As a result of a property test, even if the photosensitive film was peeled from the copper foil, part of the film did not remain on the copper foil, and the copper foil could be peeled off without wrinkling.

The protective film of the photosensitive dry film resist had a peel strength of 1.0 Pa · m, and the support film had a peel strength of 2.0 Pa · m. In addition, when a developability test was conducted, it was 100 μm × 100 μ
The m-square hole was developed and passed.

[0086]

Example 2 (Synthesis of Modified Polyimide) 20.8 g (0.020 mol) of the polyimide synthesized in Example 1 was added to dioxolane 80.
g, and 0.030 g of 4-methoxyphenol was added and dissolved while warming in an oil bath at 60 ° C.
Glycidyl methacrylate 3.75 g (0.0264 mo
l) was dissolved in 5 g of dioxolane and added, and 0.01 g of triethylamine was added as a catalyst, and the mixture was heated and stirred at 60 ° C. for 6 hours. In this way, a modified polyimide was synthesized. (Preparation of photosensitive dry film resist) The components shown below were mixed to prepare a photosensitive resin composition, and a B-stage photosensitive dry film resist was prepared on a PET film by the method (1). Onto this photosensitive dry film resist having a two-layer structure, a sanitect film (thickness: 25 μm) manufactured by San-A Kaken Co., Ltd. was laminated as a protective film to prepare a three-layer structure sheet.

(E) 50 parts by weight of the modified polyimide modified above (b) 10 parts by weight of bisphenol A EO modified (m + n≈30) diacrylate (NK ester A-BPE-30 manufactured by Shin-Nakamura Chemical Co., Ltd.) Parts (f) Bisphenol F EO modified (m + n≈4) diacrylate (Aronix M-208 manufactured by Toagosei Co., Ltd.) 10 parts by weight (g) tribromophenyl acrylate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) BR-30) 30 parts by weight (h) 4,4'-bis (diethylamino) benzophenone) 1 part by weight (i) 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone 1 part by weight When the tackiness test of this photosensitive film was performed, even if the photosensitive film was peeled from the copper foil, part of the film did not remain on the copper foil and the copper foil could be peeled without wrinkling. It was

The peel strength of the protective film of this photosensitive dry film resist was 1.0 Pa · m, and the peel strength of the support film was 6.0 Pa · m, which was acceptable. In addition, when a developability test was conducted, it was 100 μm.
The hole of 100 μm square was developed, and the result was acceptable.

[0089]

Example 3 The components shown below were mixed to prepare a photosensitive resin composition, and a B-stage photosensitive dry film resist was prepared on a PET film by the method (1). Onto this photosensitive dry film resist having a two-layer structure, a sanitect film (thickness: 25 μm) manufactured by San-A Kaken Co., Ltd. was laminated as a protective film to prepare a three-layer structure sheet.

(E) 55 parts by weight of the modified polyimide modified in Example 2 (b) Bisphenol A EO modified (m + n≈30) diacrylate (NK ester A-BPE-30 manufactured by Shin-Nakamura Chemical Co., Ltd.) 10 parts by weight (f) Bisphenol F EO modified (m + n≈4) diacrylate (Aronix M-208 manufactured by Toagosei Co., Ltd.) 20 parts by weight (j) Silicone (XC99-B5664 manufactured by Toshiba Silicone) 15 parts by weight Parts (h) 4,4'-bis (diethylamino) benzophenone) 1 part by weight (i) 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone 1 part by weight Adhesion of this photosensitive film When a property test was conducted, even if the photosensitive film was peeled off from the copper foil, part of the film did not remain on the copper foil, and the copper foil could be peeled off without wrinkling.

The peel strength of the protective film of this photosensitive dry film resist was 3.5 Pa · m, and the peel strength of the support film was 6.0 Pa · m, which was acceptable. In addition, when a developability test was conducted, it was 100 μm.
× 100 μm square hole was developed and was passed.

[0092]

Example 4 The components shown below were mixed to prepare a photosensitive resin composition, and a B-stage photosensitive dry film resist was prepared on a PET film by the method (1). A protective (# 6221F) film (50 μm thick) manufactured by Sekisui Chemical Co., Ltd. was laminated as a protective film on the photosensitive dry film resist having the two-layer structure to prepare a three-layer structure sheet.

(E) 40 parts by weight of the modified polyimide modified in Example 2 (b) bisphenol A EO modified (m + n≈30) diacrylate (NK ester A-BPE-30 manufactured by Shin-Nakamura Chemical Co., Ltd.) 5 parts by weight (f) Bisphenol F EO modified (m + n≈4) diacrylate (Aronix M-208 manufactured by Toagosei Co., Ltd.) 30 parts by weight (c) TPP (triphenyl phosphate) 10 parts by weight (g) Tribromophenyl acrylate (BR-30 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 15 parts by weight (h) 4,4'-bis (diethylamino) benzophenone) 1 part by weight (i) 3,3 ', 4,4'- Tetra (t-butylperoxycarbonyl) benzophenone 1 part by weight When an adhesion test of this photosensitive film was conducted, it was confirmed that a part of the film remained on the copper foil even if the photosensitive film was peeled from the copper foil. No, and the copper foil is wrinkled It could be peeled off without becoming. The protective film of this photosensitive dry film resist had a peel strength of 21 Pa · m, and the support film had a peel strength of 120 Pa · m, which were acceptable. Further, when a developing property test was conducted, a hole of 100 μm × 100 μm square was developed and was passed.

[0094]

Comparative Example 1 A photosensitive resin composition was prepared by mixing the following components without using a polyimide resin, and a B-stage photosensitive dry film resist was prepared on a PET film by the method (1). . Onto this photosensitive dry film resist having a two-layer structure, a Santec Chemical Co., Ltd. Sanitect film was laminated as a protective film to prepare a three-layer structure sheet. (J) Copolymer copolymer synthesized at a copolymerization ratio (weight basis) of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid = 55/8/15/22 50 parts by weight (b) Bisphenol A EO Modified (m + n≈30) diacrylate (NK ester A-BPE-30 manufactured by Shin-Nakamura Chemical Co., Ltd.) 10 parts by weight (f) Bisphenol F EO modified (m + n≈4) diacrylate (Toago Synthetic Co., Ltd. Aronix M-208 10 parts by weight (c) TPP (triphenyl phosphate) 10 parts by weight (g) Tribromophenyl acrylate (Daiichi Kogyo Seiyaku Co., Ltd. BR-30) 20 parts by weight (h ) 4,4'-bis (diethylamino) benzophenone) 1 part by weight (i) 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone 1 part by weight Was subjected to wear testing, upon the release of the photosensitive film from the copper foil, the stickiness of the photosensitive film, a portion of the photosensitive resin remaining on a copper foil,
Also, the copper foil was pulled and wrinkled.

The peeling strength of the protective film of this photosensitive dry film resist was 150 Pa · m, and the peeling strength of the support film was 300 Pa · m.

Thus, when a photosensitive film is produced using a copolymer which is not a polyimide resin, stickiness occurs.

[0097]

Comparative Example 2 A photosensitive resin composition was prepared by mixing the following components, a B-stage photosensitive dry film resist was prepared on a PET film by the method (1), and the components shown below were mixed. Then, the photosensitive resin composition was prepared, and a B-stage photosensitive dry film resist was prepared on the PET film by the method (1). As a protective film, a Sekisui Chemical Co., Ltd. Protect (# 6221F) film (thickness 50 μm) was laminated to produce a three-layer structure sheet. (J) Copolymer polymer synthesized at a copolymerization ratio (weight basis) of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid = 55/8/15/22 60 parts by weight (f) Bisphenol F EO Modified (m + n≈4) diacrylate (Aronix M-208 manufactured by Toagosei Co., Ltd.) 15 parts by weight (k) Epoxy resin (Epicoat 828 manufactured by Toagosei Co., Ltd.) 5 parts by weight (c) TPP (triphenyl) Phosphate) 5 parts by weight (g) Tribromophenyl acrylate (BR-30 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 15 parts by weight (d) Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty. Chemicals Co., Ltd. Irgacure 819) 1 part by weight When this photosensitive film was tested for tackiness, When you try to peel from the foil, the stickiness of the photosensitive film, a portion of the photosensitive resin remaining on the copper foil.

As described above, the photosensitive film containing an acrylic resin and an epoxy resin as main components is extremely sticky.

[0099]

Comparative Example 3 A photosensitive resin composition was prepared by mixing the following components, and a B-stage photosensitive dry film resist was prepared on a PET film by the method (1). As a protective film, polyethylene film (thickness 12.5
μm) was laminated to prepare a three-layer structure sheet. (J) Methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid = 55/8/15/22 copolymerization ratio (weight basis) synthesized copolymer 40 parts by weight (b) Bisphenol A EO Modified (m + n≈30) diacrylate (Shin-Nakamura Chemical Co., Ltd. NK ester A-BPE-30) 10 parts by weight (f) Bisphenol F EO modified (m + n≈4) diacrylate (Toagosei ( Aronix M-208) 45 parts by weight (c) TPP (triphenyl phosphate) 5 parts by weight (d) Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals Co., Ltd.) Irgacure 819) 1 part by weight When the tackiness test of this photosensitive film was conducted, a part of the photosensitive resin did not remain on the copper foil. But the stickiness of the film when you try to peel the photosensitive film from the copper foil, the copper foil became wrinkled.

The peeling strength of the protective film of this photosensitive dry film resist was 150 Pa · m, and the peeling strength of the support film was 220 Pa · m, which was unacceptable because the peeling strength was too strong.

Thus, the acrylic resin content% is 50%.
When the photosensitive dry film resist is more than wt%, the peel strength of the protective film and the support film is too strong due to stickiness.

[0102]

As described above, the photosensitive dry film resist according to the present invention has a very low tackiness of the film at room temperature and thus has very good workability, and further has a good peeling property between the protective film and the support film. Therefore, the protective film can be easily peeled off, and the support film can be peeled off without applying an excessive force after pattern exposure and before development.

Further, (A) soluble polyimide, (B)
(Meth) acrylic compound, (C) phosphorus and / or compound containing siloxane moiety,
(D) By using a photosensitive resin composition containing a photoreaction initiator and / or a sensitizer as essential components, a photosensitive dry composition which has excellent flame retardancy and heat resistance and which can be developed with an alkaline aqueous solution. A film resist can be produced.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03F 7/037 501 G03F 7/037 501 7/075 7/075 7/11 501 7/11 501 7/38 501 7/38 501 H05K 3/28 H05K 3/28 DF Term (reference) 2H025 AB11 AB15 AC01 AD01 BC14 BC19 BC32 BC42 BC69 CA01 CA27 CB25 CC20 EA08 FA01 2H096 AA26 BA05 BA20 CA20 DA00 JA02 LA16 4J011 PA24 PA43 PA46 PA46 PA46 PA46 PA46 PA46 PA46 PA99 PB29 PB40 PC02 PC08 4J026 AA21 AB34 AB35 AB44 BA07 BA15 BA21 BA22 BA27 BA28 BA29 BA30 BA39 BA40 BA41 BA43 BA50 DB06 DB11 DB15 DB29 DB30 DB36 GA06 5E314 AA24 AA27 AA36 BB01 CC01 CC15 FF01 FF06 GG24

Claims (18)

[Claims] 1. A photosensitive dry film resist in a B-stage state, which is adhered to a copper foil even when laminated on a glossy surface of a copper foil at a substrate temperature of 20 ° C., a roll temperature of 20 ° C. and a pressure of 1500 Pa · m. A photosensitive dry film resist, which can be peeled off without any action. 2. The photosensitive dry film resist according to claim 1, wherein the temperature at which the PI film in the B stage state and the glossy surface of the copper foil can be pressure-bonded is 50 ° C. to 150 ° C. 3. A two-layer structure sheet obtained by laminating a support film and a photosensitive film, wherein the peel strength between the support film and the photosensitive film is 0.5 Pa · m or more and 2 or more.
The photosensitive dry film resist according to claim 1 or 2, which has a viscosity of 00 Pa · m or less. 4. A three-layer structure sheet comprising a support film, a photosensitive film and a protective film laminated in this order, wherein the peel strength between the support film and the photosensitive film is:
3. The photosensitive dry film resist according to claim 1, wherein the photosensitive dry film resist is 0.5 Pa · m or more and 200 Pa · m or less. 5. A three-layer structure sheet obtained by laminating a support film, a photosensitive film and a protective film in this order, wherein the peel strength between the protective film and the photosensitive film is 0.1 Pa in an environment where the temperature is 20 ° C.・ More than m and 100 Pa ・ m
It is the following, The 1 or 2 or 4 characterized by the following.
The photosensitive dry film resist according to any one of items. 6. The peel strength between the support film and the photosensitive film is 1.2 times or more and 5 times or less the peel strength between the protective film and the photosensitive film.
Alternatively, a photosensitive dry film resist comprising the three-layer structure sheet according to any one of 2 and 3 to 5. 7. The photosensitive dry film resist according to claim 1, wherein the photosensitive film contains polyimide. 8. A photosensitive film comprising a photosensitive resin composition containing (A) a soluble polyimide and (B) a (meth) acrylic compound containing at least one carbon-carbon double bond as essential components. The photosensitive dry film resist according to claim 1, wherein 9. A photosensitive film comprising a photosensitive resin composition containing, as an essential component, a compound containing phosphorus and / or halogen and / or a siloxane moiety in addition to the components (A) and (B). Claims 1 to 1 characterized in that
8. The photosensitive dry film resist as described in any one of 8 above. 10. The component (A) is 30 to 70% by weight based on the total amount of the components (A), (B) and (C),
5 to 50% by weight of the component (B) and 1 to 5 of the component (C)
It is a photosensitive film produced from the photosensitive resin composition containing 0 weight%, The photosensitive dry film resist as described in any one of Claims 1-9 characterized by the above-mentioned. 11. The photosensitive resin according to claim 9, which further comprises (D) a photoreaction initiator and / or a sensitizing dye in addition to the components (A), (B) and (C). A photosensitive dry film resist, which is a photosensitive film produced from the composition. 12. The photosensitive dry film resist according to claim 1, wherein the thickness of the photosensitive film is 5 to 75 μm. 13. The photosensitive dry film resist according to claim 1, wherein the support film has a thickness of 5 to 50 μm. 14. A protective film having a thickness of 5 to 50 μm, as claimed in claim 1 or 2, or 4 to 13.
The photosensitive dry film resist according to any one of items. 15. A flexible printed wiring board using the photosensitive dry film resist according to claim 1 as a cover lay. 16. A head for a hard disk drive of a personal computer, wherein the photosensitive dry film resist according to claim 1 is used as a coverlay. 17. A step of applying an organic solvent solution of a photosensitive resin composition containing the components (A) and (B) according to any one of claims 8 to 11 onto a support film and drying the solution. A method for producing a photosensitive film comprising a two-layer structure sheet. 18. A method for producing a photosensitive film, which comprises a step of laminating a protective film on the photosensitive film comprising the two-layer structure sheet according to claim 17.