JP2008304849A - Photosensitive dry film resist, printed wiring board using same and method for producing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive dry film resist which can be developed with a water-based developer and excels in resolution, flame retardancy, adhesion, moisture resistance, electric reliability and storage stability, a method for producing the same and a method for utilizing these. <P>SOLUTION: The photosensitive dry film resist has a multilayer structure including at least a first photosensitive layer and a second photosensitive layer, wherein the first photosensitive layer contains (A1) a binder polymer, (B1) a (meth)acrylic compound, (C1) a photoreaction initiator and (D1) a metal hydrate as a flame retardant as essential components, and the second photosensitive layer contains (A2) a binder polymer and (B2) a (meth)acrylic compound as essential components and does not substantially contain (D2) a flame retardant. In relation to the flame retardant (D2), the second photosensitive layer has a flame retardant content of 0-10 wt.%, and when a flame retardant content of the first photosensitive layer is considered to be 100, a flame retardant content of the second photosensitive layer is 0-50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive dry film resist, a printed wiring board using the same, and a method for producing a printed wiring board, and in particular, water-based development is possible, and resolution, flame retardancy, adhesion, and moisture resistance. The present invention relates to a photosensitive dry film resist excellent in electrical reliability, a printed wiring board using the same, and a method for manufacturing the printed wiring board.

  In recent years, electronic devices used in these electronic devices are required to be further reduced in size and weight as the electronic devices become more functional, smaller and lighter. For this reason, it is required to increase the functionality and performance of electronic components by performing high-density mounting of semiconductor elements, etc. on printed wiring boards, miniaturization of wiring, and multilayering of printed wiring boards. ing. Further, in order to cope with the miniaturization of the wiring, an insulating material having higher electrical insulation is required to protect the wiring.

  When the printed wiring board is manufactured, a photosensitive material is used for various purposes. That is, formation of a patterned circuit (pattern circuit) on the substrate of the printed wiring board, formation of a protective layer for protecting the printed wiring board surface and the pattern circuit, formation of an interlayer insulating layer of the multilayer printed wiring board, etc. In addition, a photosensitive material is used.

  For example, taking the formation of a protective layer for protecting the printed wiring board surface and pattern circuit as an example, the use of a photosensitive material has the following advantages. A flexible flexible printed circuit board (hereinafter also referred to as “FPC”) is bonded with a polymer film called a coverlay film on the surface for the purpose of protecting the conductor surface. Conventionally, epoxy and acrylic adhesives have been mainly used for bonding the FPC and the coverlay film. However, the methods using these adhesives have problems such as (1) low heat resistance such as solder heat resistance and adhesive strength at high temperature, and (2) poor flexibility, and are used as coverlay films. The performance of the polymer film was not fully utilized.

  Further, when the FPC and the coverlay film are bonded together using the adhesive, the alignment for bonding the coverlay film to the correct position on the FPC is almost manual. Therefore, workability and position accuracy are poor and cost is high.

  In order to improve the workability and position accuracy, a method of forming a protective layer by coating and drying a photosensitive resin composition solution on the conductor surface of an FPC, a film-like photosensitive dry film resist (photosensitive cover layer). A method of laminating a film (also called a film) has been developed. In these methods, a photomask is placed on the formed photosensitive resin layer for exposure and development, so that workability and positional accuracy are improved.

  As described above, the photosensitive material includes a liquid photosensitive material and a film-like photosensitive material. Among these, the film-like photosensitive material has advantages such as excellent film thickness uniformity and workability compared to the liquid photosensitive material. Therefore, a resist film for pattern circuit used for forming a pattern circuit (photosensitive dry film resist used for forming a pattern circuit), a photosensitive coverlay film used for forming the protective layer, and a photosensitivity used for forming the interlayer insulating layer. Various film-like photosensitive materials, such as dry film resists, are also used depending on the application.

  As the above-described photosensitive coverlay film and photosensitive dry film resist (hereinafter, both are collectively referred to as photosensitive dry film resist), acrylic films are currently on the market. It was limited.

  Regarding the improvement of flame retardancy, there is a photosensitive dry film resist produced by curing a photosensitive resin composition containing a brominated flame retardant (see, for example, Patent Document 1). However, since flame retardants containing halogens may adversely affect the environment, studies on non-halogen flame retardants are underway in place of brominated flame retardants.

  Examples of non-halogen flame retardants include nitrogen and phosphorus. However, nitrogen-based compounds are difficult to put into practical use in consideration of the effect on the curability of the resin. When phosphorus-based compounds are used, the hygroscopicity of the resin composition tends to increase, and the moisture resistance and electrical reliability are high. There has been a problem of reduction (see, for example, Patent Document 2).

  On the other hand, a method of achieving both moisture resistance and flame retardancy by laminating a resin layer having moisture resistance and a resin layer having flame retardancy has been proposed. However, since this is not photosensitive, it does not correspond to microfabrication and is used in different fields (see, for example, Patent Documents 3 and 4).

  Furthermore, in the field of the photosensitive film, there are some which are multi-layered, but these are for the purpose of improving the photosensitive characteristics and are not intended to improve the flame retardancy, moisture resistance, and electrical reliability. (For example, refer patent document 5 etc.). Patent Document 5 describes a photosensitive transfer sheet composed of two photosensitive layers and barrier layers having different photosensitivities, and as an effect thereof, desired patterns having different thicknesses can be easily formed in an image. It describes what you can do.

  By the way, as the photosensitive dry film resist, an acrylic resin has been conventionally used. However, a photosensitive dry film resist made of an acrylic resin has insufficient heat resistance and mechanical strength of the film. Therefore, in order to improve the heat resistance and the mechanical strength of the film, it has been proposed to use a photosensitive polyimide using a polyimide having excellent heat resistance among various organic polymers as a photosensitive dry film resist or the like. Yes.

  So far, various photosensitive polyimide compositions have been studied for the purpose of use in semiconductor applications, and polyamic acid (polyimide precursor) has a tertiary amine and a (meth) acryloyl group. An ion-bonded photosensitive polyimide obtained by mixing a compound to form a photosensitive polyimide, an ester-bonded photosensitive polyimide having a methacryloyl group introduced into the carboxyl group of the polyamic acid via an ester bond, an isocyanate compound having a methacryloyl group, A photosensitive polyimide introduced into a carboxyl group part of a polyamic acid (polyimide precursor), a photosensitive polyimide mixed with a polyamic acid and a (meth) acrylic compound, and the like have been reported.

  Among these, the photosensitive polyimide (refer patent documents 6-9 etc.) which mixed the polyamic acid and the (meth) acrylic-type compound is used as a photosensitive resin composition which manufactures the dry film for FPC coverlay materials. It has been reported to be used. In these patent documents 6 to 9, by using a photosensitive polyimide in which a polyamic acid and a (meth) acrylic compound are mixed, it is possible to develop with an alkaline aqueous solution that is more preferable than an organic solvent from the viewpoint of work safety, and a film after exposure. Have been reported to sufficiently cure, exhibit high extensibility, and the like.

Furthermore, in order to improve the flexibility and flexibility of a dry film used as an FPC coverlay material, a photosensitive resin composition using polyamic acid obtained from polysiloxane diamine as a raw material and a (meth) acrylic compound Has been proposed (see, for example, Patent Document 10).
JP 2001-335619 A (published on December 4, 2001) JP 2000-241969 A (published September 8, 2000) JP 2004-311573 A (published on November 4, 2004) JP 2005-161778 A (published June 23, 2005) Japanese Patent Laying-Open No. 2005-202066 (published July 28, 2005) JP 11-52569 A (published February 26, 1999) Japanese Patent Laying-Open No. 2001-5180 (published January 12, 2001) Japanese Patent Laying-Open No. 2004-29702 (published on January 29, 2004) JP 2000-98604 A (published April 7, 2000) JP 2004-361883 A (published on December 24, 2004)

  However, none of the above conventional photosensitive dry film resists have sufficient performance, and developability with an aqueous developer; excellent resolution, flame retardancy, adhesion, moisture resistance, and electrical reliability. There is no one that satisfies the criteria.

  As described above, there has been reported a photosensitive resin composition that is made flame retardant by introducing a phosphorus-based flame retardant into a polyamic acid and a (meth) acrylic compound. In such a photosensitive resin composition, flame retardant is achieved by introducing a flame retardant, but when a phosphorus compound is used as the flame retardant, the hygroscopicity of the resin composition tends to be high, and the moisture resistance is high. There exists a problem that it falls, and also electrical reliability falls.

  Moreover, in the photosensitive resin composition using the polyamic acid and the (meth) acrylic compound obtained using the polysiloxane diamine described in Patent Document 10 as described above, the flexibility / flexibility is improved. Since the flame retardancy of the polyimide itself obtained from the polyamic acid used is poor, a large amount of flame retardant is required, and therefore there is a problem that the electrical reliability is inferior.

  On the other hand, Patent Documents 3 and 4 propose a method for achieving both moisture resistance and flame retardancy by laminating a resin layer having moisture resistance and a resin layer having flame resistance. However, this does not apply to the photosensitive resin, and does not support fine processing.

  Also, in the field of photosensitive films, there have been reports on films that have been multilayered for the purpose of improving photosensitive characteristics, but these are aimed at improving photosensitive characteristics, and are flame retardant, moisture resistant, There is nothing that improves electrical reliability.

  An object of the present invention is to provide a photosensitive dry film resist capable of aqueous development and having excellent resolution, flame retardancy, adhesion, moisture resistance, and electrical reliability, and a method for using the same.

  In the present invention, the first photosensitive layer contains (A1) a binder polymer, (B1) a (meth) acrylic compound, (C1) a photoreaction initiator, and (D1) a metal hydrate as an essential component as a flame retardant. The second photosensitive layer contains (A2) a binder polymer and (B2) a (meth) acrylic compound as essential components, (D2) contains substantially no flame retardant, and (D2) The ratio of the weight of the flame retardant (D1) to the total weight of one photosensitive layer is the flame retardant content of the first photosensitive layer, and the ratio of the weight of the flame retardant (D2) to the total weight of the second photosensitive layer is When the flame retardant content of the second photosensitive layer is 0 to 10% by weight and the flame retardant content of the first photosensitive layer is 100, the second photosensitive layer Satisfies the condition that the flame retardant content of the layer is from 0 to 50 Wherein the bets are photosensitive dry film resist of a multilayer structure including at least a first photosensitive layer and the second photosensitive layer.

  The second photosensitive layer preferably further contains (C2) a photoreaction initiator as an essential component.

  In the multilayer dry photosensitive resist, the second photosensitive layer is preferably located in the outermost layer of the multilayer structure, and the first photosensitive layer is preferably located in another outermost layer.

  In the photosensitive dry film resist according to the present invention, the metal hydrate as the flame retardant (D1) and / or the metal hydrate as the flame retardant (D2) is an aluminum hydroxide compound or a magnesium hydroxide compound. Is preferred.

  The (A1) binder polymer and / or (A2) binder polymer is preferably a carboxyl group-containing vinyl polymer. The (A1) binder polymer and / or (A2) binder polymer is preferably a polyamic acid, and is a polyamic acid using a polysiloxane diamine represented by the general formula (1) as a part of the raw material. Is more preferable.

(In the formula, each R1 independently represents a hydrocarbon having 1 to 5 carbon atoms, each R2 independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, and n is Represents an integer of 1 to 20.)

  The (A1) binder polymer and / or (A2) binder polymer is represented by the following general formula (2):

(Wherein R1 represents a tetravalent organic group, R2 each independently represents an alkylene group having 2 to 5 carbon atoms, R3 each independently represents a methyl group or a phenyl group, The phenyl group content is 15% or more and 40% or less, and m is an integer of 4 or more and 20 or less.
The following general formula (3)

(In the formula, R4 represents a tetravalent organic group, and R5 represents a divalent organic group obtained by removing two amino groups from an aromatic diamine.)
The polyamic acid which consists of a structural unit represented by these may be sufficient.

  In the photosensitive dry film resist according to the present invention, the polyamic acid is further represented by the following general formula (4).

(Wherein R6 represents a tetravalent organic group, and R7 represents the following chemical formulas a, b, c, d, e, f or g:

In the chemical formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in the chemical formula f, R8 represents a hydrogen atom, a methyl group, An ethyl group or a butyl group is shown. )
It may have a structural unit represented by

The (A1) binder polymer and / or (A2) binder polymer is represented by the following general formula (4):

(Wherein R6 represents a tetravalent organic group, and R7 represents the following chemical formulas a, b, c, d, e, f or g:

In the chemical formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in the chemical formula f, R8 represents a hydrogen atom, a methyl group, An ethyl group or a butyl group is shown. )
A structural unit represented by
The following general formula (3)

(In the formula, R4 represents a tetravalent organic group, and R5 represents a divalent organic group obtained by removing two amino groups from an aromatic diamine.)
It may consist of a structural unit represented by

  In the photosensitive dry film resist having a multilayer structure according to the present invention, the structural unit represented by the general formula (3) is the two amino groups of the aromatic diamine in R5 in the general formula (3). It is preferable that at least one of the aromatic rings to which is bonded contains a structural unit bonded to the main chain with two bonds located at the meta position.

  The aromatic diamine is m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3′-diaminodiphenylsulfone, 3,3′-. Diaminobenzanilide, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) ) Phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) -Biphenyl, 1,3-bis (3-aminophenoxy) benzene, bis [4- (3-aminopheno) ) Phenyl] sulfone, or more preferably 2,2-bis (3-aminophenyl) propane.

  The (A1) binder polymer and / or (A2) binder polymer is preferably a soluble polyimide having a carboxyl group and / or a hydroxyl group, and the polysiloxane diamine represented by the general formula (1) is a part of the raw material. More preferably, it is a soluble polyimide having a carboxyl group and / or a hydroxyl group.

(In the formula, each R1 independently represents a hydrocarbon having 1 to 5 carbon atoms, each R2 independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, and n is Represents an integer of 1 to 20.)
When the thickness of the first photosensitive layer is 100, the thickness of the second photosensitive layer is preferably 500 or less.

  Another invention of the present invention is a printed wiring board using the multilayer dry photosensitive dry film resist as an insulating protective layer.

  In the printed wiring board, in the configuration in the photosensitive dry film resist, which is a part of the configuration of the printed wiring board, the second photosensitive layer is located on the outermost layer in contact with the circuit surface, and the first photosensitive layer It is preferred that the layer is located on the other outermost layer.

  In order to solve the above problems, the method for producing a printed wiring board according to the present invention is characterized in that the photosensitive dry film resist is cured at a temperature of 180 ° C. or less to form an insulating protective layer.

  As described above, in the photosensitive dry film resist according to the present invention, the first photosensitive layer has (A1) binder polymer, (B1) (meth) acrylic compound, (C1) photoreaction initiator, and (D1) difficult. Metal hydrate is contained as an essential component as a flame retardant, the second photosensitive layer contains (A2) a binder polymer and (B2) (meth) acrylic compound as essential components, and (D2) a flame retardant is substantially contained. Not contained (D2) With respect to the flame retardant, the ratio of the weight of the flame retardant (D1) to the total weight of the first photosensitive layer is the flame retardant content of the first photosensitive layer and the total weight of the second photosensitive layer (D2). When the ratio of the weight of the flame retardant is the flame retardant content of the second photosensitive layer, the flame retardant content of the second photosensitive layer is from 0 to 10% by weight, and the first photosensitive layer has a difficulty. When the flame retardant content is 100, the difficulty of the second photosensitive layer Since agent content has a configuration is 0 or more and 50 or less, an aqueous developing property is satisfactory, and flame retardancy, adhesion, moisture resistance, and is excellent in electric reliability. Furthermore, the multi-layer structure is excellent in photosensitivity such as resolution.

  Therefore, the present invention can be suitably used not only in the industry for manufacturing printed wiring boards such as FPC, for example, in the resin industry for manufacturing resin materials for electronic components, but also in electronic devices using such printed wiring boards. There is an effect that it can be suitably used in the industrial field.

  As a result of intensive studies in view of the above problems, the present inventors have found that a photosensitive dry film resist includes a first photosensitive layer containing a flame retardant and a second photosensitive material containing no flame retardant or containing a small amount of flame retardant. And a photosensitive dry film resist having both excellent flame retardancy and electrical reliability when laminated so that the second photosensitive layer is in contact with the side in contact with the laminate on which the circuit is formed. I found out that Surprisingly, it has been found that the obtained photosensitive dry film resist not only has flame retardancy and electrical reliability, but also has improved photosensitivity as compared to a one-layer structure.

  Hereinafter, the photosensitive dry film resist and the printed wiring board using the same according to the present invention will be described in the order of (I) photosensitive dry film resist, (II) method for producing photosensitive dry film resist, and (III) printed wiring board. I will explain it.

(I) Photosensitive dry film resist (I-1) Photosensitive dry film resist The photosensitive dry film resist according to the present invention is a multilayer dry photosensitive resist comprising at least a first photosensitive layer and a second photosensitive layer. It is.

  Note that in this specification, a multilayer structure refers to a structure composed of two or more layers. Therefore, the photosensitive dry film resist having a multilayer structure according to the present invention may have a two-layer structure composed of a first photosensitive layer and a second photosensitive layer, or a layer in which other layers are laminated. It may be.

  The photosensitive dry film resist having a multilayer structure according to the present invention includes at least a first photosensitive layer and a second photosensitive layer, and the first photosensitive layer is (A1) a binder polymer, (B1) a (meth) acrylic compound, It contains (C1) a photoreaction initiator and (D1) a metal hydrate as a flame retardant as an essential component, and the second photosensitive layer contains (A2) a binder polymer, and (B2) a (meth) acrylic compound. It is contained as an essential component, (D2) substantially contains no flame retardant, and (D2) the flame retardant of the first photosensitive layer is the ratio of the weight of the flame retardant (D1) to the total weight of the first photosensitive layer. When the ratio of the content and the weight of the flame retardant (D2) to the total weight of the second photosensitive layer is the flame retardant content of the second photosensitive layer, the flame retardant content of the second photosensitive layer is 0 or more and 10 % By weight or less and the first photosensitive layer If the flame retardant content is 100, which satisfies the condition of that the flame retardant content of the second photosensitive layer is 0 or more and 50 or less. The second photosensitive layer preferably further contains (C2) a photoreaction initiator as an essential component. Further, such a photosensitive dry film resist is used by being laminated so that the second photosensitive layer is in contact with the side in contact with the copper-clad laminate (also referred to as CCL with circuit) on which a circuit is formed. The first photosensitive layer is preferably located in the outermost layer as viewed from the CCL side.

  Here, (D2) substantially (substantially) not containing a flame retardant means that (D2) contains no flame retardant at all or contains a slight amount, When the flame retardant content of the second photosensitive layer is 0 or more and 10 wt% or less and the flame retardant content of the first photosensitive layer is 100, the flame retardant of the second photosensitive layer It means that the content is from 0 to 50. In other words, the flame retardant content of the second photosensitive layer is from 0 to 10% by weight, and 0 ≦ (flame retardant content of the second photosensitive layer) / (flame retardant content of the first photosensitive layer) ) ≦ 0.5.

  In the photosensitive dry film resist having a multilayer structure of the present invention, flame retardancy is imparted by increasing the flame retardant content of the first photosensitive layer, and the flame retardant content of the second photosensitive layer is decreased or difficult. By not containing any flame retardant, moisture resistance and electrical reliability can be further improved. Furthermore, it becomes difficult to generate a residue during alkali development, and the developability and resolution can be further improved.

  By adopting such a configuration, the photosensitive dry film resist as a whole has good aqueous developability and excellent flame retardancy, adhesion, moisture resistance, and electrical reliability.

  The flame retardant content of the second photosensitive layer may be 0 or more and 10% by weight or less, but is preferably less, more preferably 5% by weight or less, and further preferably 1% by weight or less. preferable. If the flame retardant content of the second photosensitive layer is less than 10% by weight, the resolution, moisture resistance, and electrical reliability can be further improved. Further, (the flame retardant content of the second photosensitive layer) / (the flame retardant content of the first photosensitive layer) may be from 0 to 0.5, more preferably 0.2 or less, It is more preferably 0.1 or less, and particularly preferably 0.05 or less. When the flame retardant content of the second photosensitive layer is within the above range by setting (the flame retardant content of the second photosensitive layer) / (the flame retardant content of the first photosensitive layer) to 0.5 or less. Sufficient flame retardancy can be imparted to the entire photosensitive dry film resist.

In the present invention, the flame retardant content means the ratio of the weight of the flame retardant to the weight of all components in each layer constituting the photosensitive dry film resist, and is calculated by the following formula. . When D2, C2, E1, and E2 do not exist, the weight is assumed to be 0. E1 and E2 represent all components other than A to D.
Flame retardant content of first photosensitive layer (% by weight) = ((D1) weight of flame retardant) ÷ {((A1) binder polymer weight) + ((B1) (meth) acrylic compound weight) + ( (C1) Weight of photoinitiator) + (Weight of (D1) Flame retardant) + Weight of ((E1) Other components)} × 100
Flame retardant content of second photosensitive layer (% by weight) = ((D2) weight of flame retardant) ÷ {((A2) weight of binder polymer) + ((B2) (meth) acrylic compound weight) + ( (C2) Weight of photoinitiator) + ((D2) Weight of flame retardant) + ((E2) Weight of other components)} × 100
The photosensitive dry film resist according to the present invention is a photosensitive dry film resist having a multilayer structure including at least a first photosensitive layer and a second photosensitive layer as described above, and includes a first photosensitive layer and a second photosensitive layer. However, if the content of the flame retardant in each layer includes the above-described components, the ratio of the binder polymer, the (meth) acrylic compound, the photoreaction initiator, and the flame retardant in each layer is as follows. There is no particular limitation.

  In the first photosensitive layer and the second photosensitive layer, the ratio of the weight of the (A1) binder polymer to the total weight of the first photosensitive layer and the ratio of the weight of the (A2) binder polymer to the total weight of the second photosensitive layer. Are preferably 10% by weight or more and 90% by weight or less, more preferably 20% by weight or more and 85% by weight or less, and further preferably 25% by weight or more and 80% by weight or less. When the ratio is 10% or more, the heat resistance of the first photosensitive layer and the second photosensitive layer tends to be improved, and when the ratio is 90% or less, it is possible to press the substrate at a low temperature. Therefore, it is preferable.

  In the first photosensitive layer and the second photosensitive layer, (B1) (meth) acrylic compound and (B2) (meth) acrylic compound are respectively (A1) 100 parts by weight of the binder polymer and (A2). It is preferably contained in the range of 1 part by weight or more and 400 parts by weight or less, more preferably 3 parts by weight or more and 300 parts by weight or less with respect to 100 parts by weight of the binder polymer. When the (meth) acrylic compound is contained within the above range, the first photosensitive layer and the second photosensitive layer that are imidized at a low temperature can be realized particularly effectively as compared with the conventional one.

  In the first photosensitive layer and the second photosensitive layer, the (C1) photoinitiator and the (C2) photoinitiator each have a sensitizing effect and do not adversely affect the developability. What is necessary is just to mix | blend. Specifically, the (C1) photoinitiator and (C2) photoinitiator are each 0.01 to 50 parts per 100 parts by weight of the (A1) binder polymer and (A2) binder polymer. It is preferable to blend by weight.

  If the photoinitiator of the first photosensitive layer is contained in the above ratio, even if the second photosensitive layer does not contain the (C2) photoinitiator, a photosensitive driver having a certain resolution and photosensitivity. A film resist can be obtained. Therefore, the present invention includes a configuration in which the second photosensitive layer substantially does not contain (C2) a photoreaction initiator. Therefore, the blending ratio of the (C2) photoinitiator with respect to 100 parts by weight of the (A2) binder polymer may be 0 to 0.01 parts by weight.

  In the first photosensitive layer, the content of the flame retardant (D1) is not particularly limited, and may be appropriately selected according to the type of flame retardant used. The content of the flame retardant (D1) is in the range of 5 to 50 parts by weight when the total amount of the (A1) binder polymer and (B1) (meth) acrylic compound is 100 parts by weight. Preferably, it is in the range of 10 to 40 parts by weight. (D1) When the content of the flame retardant is 5 parts by weight or more, flame retardancy can be effectively imparted to the cured photosensitive dry film resist. Furthermore, when the content of the flame retardant (D1) is 50 parts by weight or less, the mechanical properties of the photosensitive dry film resist after curing can be improved. The content of the flame retardant (D2) in the second photosensitive layer is as described above.

  Although the thickness of the photosensitive dry film resist concerning this invention is not specifically limited, For example, it is preferable that they are 5 micrometers or more and 75 micrometers or less, and it is more preferable that they are 10 micrometers or more and 60 micrometers or less. If the thickness of the photosensitive dry film resist is less than 5 μm, it may not be possible to cover a conductor wiring such as copper, which is not preferable. Further, if the thickness of the photosensitive dry film resist is larger than 75 μm, the photosensitivity may be lowered, which is not preferable.

  The thickness of the second photosensitive layer is preferably 10 to 500, more preferably 20 to 400, and further preferably 50 to 300, when the thickness of the first photosensitive layer is 100. preferable.

  When the thickness of the first photosensitive layer is 100, if the thickness of the second photosensitive layer is larger than 500, the flame retardancy of the photosensitive dry film resist is lowered, which is not preferable. Further, when the thickness of the first photosensitive layer is 100, if the thickness of the second photosensitive layer is smaller than 10, the electrical reliability tends to decrease.

  The photosensitive dry film resist according to the present invention is used by being laminated so that the second photosensitive layer is in contact with the side in contact with the copper-clad laminate (also referred to as CCL with circuit) on which a circuit is formed. Thereby, the resolution, flame retardance, moisture resistance, and electrical reliability of the photosensitive dry film resist can be improved. This is because by reducing the concentration of the flame retardant in the portion in contact with the copper clad laminate on which the circuit is formed, it is possible to prevent a decrease in moisture resistance in the portion in contact with the copper clad laminate, so that the electric This is considered to be because the reliability can be improved.

  In addition, it is considered that the resolution and the photosensitivity can be improved by laminating the second photosensitive layer in contact with the side in contact with the copper-clad laminate for the following reason. That is, the photosensitivity is manifested by the photoreaction initiator generating radicals or the like by light irradiation and the (meth) acrylic compound being crosslinked. Here, when the concentration of the flame retardant is high, the concentration of generated radicals or the like is decreased, or the crosslinking density (concentration) of the (meth) acrylic compound is decreased, and the photosensitivity is decreased. In particular, this tendency is large on the side far from the side irradiated with light (deep part). Therefore, by reducing the flame retardant concentration on the side far from the light-irradiated side, that is, on the side in contact with the copper-clad laminate, it is possible to improve resolution and photosensitivity. Furthermore, by reducing the concentration of the flame retardant in the second photosensitive layer in contact with the substrate, the alkali solubility of the second photosensitive layer is improved, so that residues are hardly generated during alkali development, and resolution and photosensitivity are improved. Can be increased. Such an effect is obtained even if the alkali solubility of the first photosensitive layer is poor as long as the alkali solubility of the second photosensitive layer in contact with the substrate is excellent. Therefore, by laminating so that the second photosensitive layer is in contact with the copper-clad laminate, it is possible to ensure the flame resistance of the entire photosensitive dry film resist and at the same time obtain the effect of excellent alkali solubility. it can.

  The photosensitive dry film resist according to the present invention may further be laminated with a support film and / or a protective film described later. The support film is formed outside the first photosensitive layer, and the protective film is formed outside the second photosensitive layer.

  Hereinafter, the respective components contained in the first photosensitive layer and the second photosensitive layer constituting the photosensitive dry film resist having a multilayer structure according to the present invention will be described in detail.

(I-2) Binder polymer In the present invention, the binder polymer is a polymer component blended to impart film-forming ability among the photosensitive resin composition used for forming a photosensitive dry film resist. Refers to that. In the present invention, the polymer component refers to an oligomer or polymer component having a weight average molecular weight of 5,000 or more. The weight average molecular weight can be measured by size exclusion chromatography (SEC), for example, HLC8220GPC manufactured by Tosoh Corporation.

  The binder polymer used in the present invention is not particularly limited, but is preferably soluble in an aqueous alkaline solution or swellable in order to enable aqueous development, so that a carboxyl group, a hydroxyl group, and a sulfonic acid group are present in the polymer chain. It preferably contains an acidic functional group such as a phosphate group. Examples of the binder polymer having an acidic functional group include a carboxyl group-containing vinyl polymer, a polyamic acid, a soluble polyimide having a carboxyl group and / or a hydroxyl group, and can be used alone or in combination of two or more.

  In the present invention, (A1) and (A2) may be the same binder polymer or different. Similarly, for the components B, C, D, and E, the same material may be used for the first photosensitive layer and the second photosensitive layer, or different materials may be used.

(I-2-1) Carboxyl group-containing vinyl polymer By using a carboxyl group-containing vinyl polymer as a binder polymer, a photosensitive dry film resist excellent in flexibility and alkali solubility can be produced. Moreover, it is easy to manufacture and is excellent in terms of production and cost.

  The carboxyl group-containing vinyl polymer can be obtained by copolymerizing a carboxyl group-containing monomer and a monomer copolymerizable therewith by a known method.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid, maleic acid monoalkyl ester, vinyl benzoic acid, cinnamic acid, propiolic acid, fumaric acid, crotonic acid, maleic anhydride, phthalic anhydride, etc. Is mentioned. Among these, (meth) acrylic acid is preferable from the viewpoints of cost, polymerizability, and the like. These can be used alone or in combination of two or more.

  Examples of the monomer copolymerizable with these include, for example, (meth) acrylic acid esters, maleic acid diesters, fumaric acid diesters, crotonic acid esters, vinyl esters, maleic acid diesters, (meth) acrylamides , Vinyl ethers, vinyl alcohols, styrene, styrene derivatives and the like. Of these, (meth) acrylic acid esters, styrene, and styrene derivatives are preferably used from the viewpoints of polymerizability and flexibility. These can be used alone or in combination of two or more.

  The carboxyl group-containing vinyl polymer obtained from these monomers is not particularly limited, but preferably contains 5 to 50 mol% of the carboxyl group-containing monomer, more preferably 15 to 40 mol%. . If the content is less than 5 mol%, the solubility in an alkaline aqueous solution tends to be poor, and if it is greater than 50 mol%, the resistance to an alkaline aqueous solution may be inferior. In addition, the content rate of a carboxyl group-containing monomer points out the ratio of the carboxyl group-containing monomer with respect to all the monomers used.

  The weight average molecular weight of the carboxyl group-containing vinyl polymer is not particularly limited, but is preferably 5,000 to 300,000, and more preferably 10,000 to 200,000. If the weight average molecular weight is less than 5,000, the photosensitive dry film resist tends to be sticky, and the film after curing tends to have poor flex resistance. On the other hand, if the weight average molecular weight is larger than 300,000, the developability of the produced photosensitive dry film resist may be lowered. The weight average molecular weight can be measured by size exclusion chromatography (SEC), for example, HLC8220GPC manufactured by Tosoh Corporation.

(I-2-2) Polyamic acid By using polyamic acid, which is a polyimide precursor, as the binder polymer, the entire photosensitive dry film resist has an aqueous developability, flame retardancy, adhesion, moisture resistance, and electrical reliability. And excellent properties such as solder heat resistance.

  Polyamic acid can be obtained by reacting diamine and acid dianhydride in an organic solvent. For example, in an inert atmosphere such as argon or nitrogen, the diamine is dissolved in an organic solvent or dispersed in a slurry to obtain a diamine solution. On the other hand, the acid dianhydride may be added to the diamine solution after being dissolved in an organic solvent or diffusing and dispersing in a slurry state, or in a solid state.

  The acid dianhydride and diamine used for synthesizing the polyamic acid are not particularly limited, but from the viewpoint of reactivity, flame retardancy, solubility in organic solvents, heat resistance, flexibility, and the like. , Aromatic acid anhydrides and aromatic diamines are preferably used.

  Examples of the aromatic acid anhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenylsulfonetetra. Carboxylic dianhydride, 2,2-bis (hydroxyphenyl) propane dibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride, 2,3', 3,4'-biphenyl ether Tetracarboxylic dianhydride, 3,4,3 ′, 4′-biphenyl ether tetracarboxylic dianhydride, biphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, 2,2′- Aromatic tetracarboxylic dianhydrides such as hexafluoropropylidenediphthalic dianhydride, 1,3,3a, 4,5,9b-hexahydro-2,5-dioxo-3-furanyl-naphtho [1,2 -C] furan-1,3-dione And the like aliphatic tetracarboxylic acid dianhydride having an aromatic ring. The above acid dianhydrides can be used alone or in combination of two or more.

  Among the above aromatic acid dianhydrides, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3, due to ease of synthesis and solubility in alkaline aqueous solution, 3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride, 3,4,3 ′, 4′-biphenyl ether tetracarboxylic dianhydride, biphenyl-3,4,3 ′, 4′-tetracarboxylic It is preferable to use at least a part of aromatic tetracarboxylic dianhydride such as acid dianhydride, 2,2′-hexafluoropropylidenediphthalic dianhydride.

  Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminophenylethane, 4,4′-diaminophenyl ether, and 3,4 ′. -Diaminophenyl ether, 3,3'-diaminophenyl ether, 4,4'-didiaminophenyl sulfide, 4,4'-didiaminophenyl 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 3,4'-diaminodiphenyl ether, 2,7-diaminofluorene, 2,2-bis (4-aminophenyl) Xafluoropropane, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-amino) Phenoxy) -biphenyl, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) fluorene, 4,4 ′-( p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino 2-trifluoromethylphenoxy) phenyl] hexafluoropropane, and 4,4′-bis [4- (4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, bis [4- (3-aminophenoxy) ) Phenyl] sulfone. The said diamine can be used individually or in combination of 2 or more types.

  Among the above aromatic diamines, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis [4- (3) are preferred because of their heat resistance and solubility in aqueous alkali solutions. -Aminophenoxy) phenyl] sulfone is preferably used at least in part.

  Needless to say, in addition to the aromatic diamine, other known diamines may be used simultaneously as part of the raw material.

  When synthesizing polyamic acid using the diamine and acid dianhydride, the reaction may be performed using at least one of each of the diamine and acid dianhydride. That is, for example, a polyamic acid can be obtained by performing a polymerization reaction in an organic solvent using a diamine component and the acid dianhydride as described above.

  At this time, if 1 type of diamine and 1 type of acid dianhydride are substantially equimolar, it will become a polyamic acid of 1 type of acid dianhydride components and 1 type of diamine components. Further, when two or more kinds of acid dianhydride components and two or more kinds of diamine components are used, the molar ratio of the total amount of plural diamine components and the molar ratio of the total amount of plural acid dianhydride components are substantially equimolar. If adjusted, a polyamic acid copolymer can be optionally obtained.

  The temperature condition for the reaction between the diamine and the acid dianhydride (polyamic acid synthesis reaction) is not particularly limited, but is preferably −20 ° C. or higher and 80 ° C. or lower, and preferably −15 ° C. or higher and 50 ° C. or lower. More preferred. If it exceeds 80 ° C., the polyamic acid may be decomposed. Conversely, if it is −20 ° C. or lower, the progress of the polymerization reaction may be slow. Moreover, what is necessary is just to set reaction time arbitrarily in the range of 10 minutes-30 hours.

  Furthermore, the organic solvent used for the polyamic acid synthesis reaction is not particularly limited as long as it is an organic polar solvent, but it is possible to select a solvent that can dissolve polyamic acid and has a boiling point as low as possible. This is advantageous.

  Specifically, examples of the organic solvent used in the polyamic acid synthesis reaction include a formamide solvent such as N, N-dimethylformamide, an acetamide solvent such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like. Examples thereof include pyrrolidone solvents such as N-vinyl-2-pyrrolidone and ether solvents such as tetrahydrofuran, dioxane and dioxolane.

  The weight average molecular weight of the polyamic acid is not particularly limited, but is preferably 5,000 to 300,000, and more preferably 10,000 to 200,000. If the weight average molecular weight is less than 5,000, the photosensitive dry film resist tends to be sticky, and the film after curing tends to have poor flex resistance. On the other hand, if the weight average molecular weight is more than 300,000, the solution viscosity becomes too high and the handling tends to be difficult, and the developability of the produced photosensitive dry film resist may be lowered. The weight average molecular weight can be measured by size exclusion chromatography (SEC), for example, HLC8220GPC manufactured by Tosoh Corporation.

  In the photosensitive resin composition in which the polyamic acid and the (meth) acrylic compound described in Patent Documents 6 to 9 are mixed, the thermal expansion of the coverlay film and the base film obtained from the photosensitive resin composition It is difficult to suppress the warpage caused by the mismatch with the coefficient. Here, the FPC has a copper foil pattern drawn on a thin base film (about 25 μm) directly or via an adhesive, and a coverlay film is formed on the surface for the purpose of protecting the conductor surface. Therefore, if a warp occurs due to a mismatch in thermal expansion coefficient between the base film and the coverlay film, it is inconvenient when mounting components or the like.

  Thus, it cannot be said that all the conventional FPC photosensitive dry film resists have sufficient performance, and developability with an aqueous developer; excellent resolution, flame retardancy, adhesion, moisture resistance, electrical reliability There was no material that satisfies all of the properties and low warpage.

  The polyamic acid using the polysiloxane diamine represented by the following general formula (1) as at least a part of the raw material as the diamine can improve flexibility, adhesion, and flexibility. Therefore, by using such polyamic acid, it is possible to produce a photosensitive dry film resist having developability; excellent resolution, flame retardancy, adhesion, moisture resistance, electrical reliability, and also low warpage. it can.

(In the formula, each R ₁ independently represents a hydrocarbon having 1 to 5 carbon atoms, each R ₂ independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, n represents an integer of 1 to 20.)

  Further, the present inventors have further found that by using a polyamic acid made from a polysiloxane diamine having a certain structure as a raw material, the flame retardancy of the polyimide itself can be further improved and a low imidization temperature can be realized. By using such polyamic acid for the photosensitive dry film resist having the above two-layer structure, developability with an aqueous developer; excellent resolution, flame retardancy, adhesion, moisture resistance, electrical reliability, and low warpage And found that a photosensitive dry film resist satisfying all of the low imidization temperatures can be realized.

  As a polyamic acid having a good balance between flame retardancy and flexibility, the following general formula (2)

(Wherein R ¹ represents a tetravalent organic group, R ² independently represents an alkylene group having 2 to 5 carbon atoms, R ³ independently represents a methyl group or a phenyl group, The phenyl group content in R ³ is 15% or more and 40% or less, and m is an integer of 4 or more and 20 or less.)
A structural unit represented by
The following general formula (3)

(In the formula, R ⁴ represents a tetravalent organic group, and R ⁵ represents a divalent organic group obtained by removing two amino groups from an aromatic diamine.)
It is also very preferable to use a polyamic acid comprising a structural unit represented by

  Thereby, the polyamic acid excellent in a flame retardance, electrical reliability, and low curvature property can be obtained. Further, by using the polyamic acid, a water-based development is possible, and a photosensitive dry film resist excellent in resolution, flame retardancy, adhesion, moisture resistance, electrical reliability, and low warpage can be obtained. .

In the general formula (2), R ¹ is not particularly limited as long as it is a tetravalent organic group, but is not limited to a monocyclic aromatic group, a condensed polycyclic aromatic group, and aromatics thereof. It is more preferable that two or more of the groups are tetravalent aromatic groups having 6 to 50 carbon atoms selected from groups connected directly or by a connecting group. Specific examples of R ¹ include a residue obtained by removing two —CO—O—CO— from an acid dianhydride described later. R ¹ may be the same or different for each structural unit represented by the general formula (2).

In general formula (2), R ² may be independently an alkylene group having 2 to 5 carbon atoms. Specifically, R ² is an ethylene group, a propylene group, a tetramethylene group, or a pentamethylene group.

In general formula (2), each R ³ is independently a methyl group or a phenyl group. Incidentally, a methyl group in R ³ is obtained polyamic acid, a photosensitive dry film resist comprising the same, and its imidized substance performance (hereinafter, in this specification, sometimes referred to as polyamic acid and the like.) A part thereof may be substituted with an ethyl group or a propyl group as long as it does not give an undesirable effect. Here, the phenyl group content in R ³ is preferably 15% or more and 40% or less. When the content of the phenyl group in R ³ is 15% or more, flame retardancy such as polyamic acid can be further improved. Thus, it is preferable that the phenyl group content is 15% or more from the viewpoint of flame retardancy of the obtained polyamic acid or the like, but if the phenyl group content is larger than 40%, the resulting polyamic acid is obtained. Since flexibility and low warpage tend to decrease, it is not preferable. The content of the phenyl group is more preferably 18% or more and 38% or less, and further preferably 20% or more and 35% or less.

  Moreover, when the content of the phenyl group is within the above range, the photosensitivity, flexibility, and electrical reliability of the resulting polyamic acid and the like tend to be improved. Thus, by setting the content of the phenyl group in the above range, the reason is not known, but the polyamic acid has less warpage, excellent flexibility, flexibility, electrical reliability, photosensitivity, and flame retardancy. Etc. can be obtained.

  Further, by improving the flame retardancy, it is possible to ensure the flame retardance with less flame retardant than the polyamic acid obtained by using the conventional polysiloxane diamine. Therefore, it is possible to obtain a polyamic acid and the like that are more excellent in terms of flame retardancy, moisture resistance, and electrical reliability.

Here, the phenyl group content means the molar fraction of the phenyl group contained in R ³ and is represented by the following formula.
The content of the phenyl group (%) = (moles of phenyl groups in R ³⁾ ÷ (moles of methyl groups in the number of moles + R ³ of the phenyl group in R ³⁾ × 100
The content of methyl groups in R ³ is preferably 85% or less than 60%. When the content of the methyl group in R ³ is 60% or more, the resulting polyamic acid is preferable because flexibility and low warpage are further improved. Further, the polyamic acid obtained when the methyl group content is 60% or more is excellent in flexibility and low warpage, but if the methyl group content is greater than 85%, the resulting polyamic acid or the like flame retardant This is not preferable because the property tends to decrease. The methyl group content is more preferably 62% to 82%, and still more preferably 65% to 80%.

  In general formula (2), the number m of repeating units of the siloxane bond is preferably an integer of 4 or more and 20 or less. It is preferable that m is 4 or more because flexibility and low warpage of the obtained polyamic acid and the like are further improved. On the other hand, if m is greater than 20, the polysiloxane sites may aggregate in the resulting polyamic acid or the like, and the aggregated domain becomes longer than the wavelength of visible light, causing light to diffuse and whiten, resulting in a decrease in photosensitivity. If m is greater than 20 and a large domain of only polysiloxane is formed, flame retardancy may be reduced. m is more preferably 4 or more and 18 or less, and further preferably 5 or more and 15 or less.

  Moreover, when the m is within the above range, the resulting polyamic acid or the like tends to be excellent in flexibility and electrical reliability. Thus, by setting m to the above range, it is possible to obtain a polyamic acid or the like having a small warpage, excellent flexibility, flexibility, electrical reliability, and photosensitivity and having flame retardancy.

In the general formula (3), R ⁴ is not particularly limited as long as it is a tetravalent organic group. More preferably, the aromatic group is a tetravalent aromatic group having 6 to 50 carbon atoms selected from a group in which two or more of the aromatic groups are directly or linked by a linking group. Specific examples of R ⁴ include a residue obtained by removing two —CO—O—CO— from an acid dianhydride described later. R ⁴ may be the same or different for each structural unit represented by the general formula (3). Moreover, it may be the same as or different from R ¹ in the general formula (2).

In general formula (3), R ⁵ is not particularly limited as long as R ⁵ is a divalent organic group obtained by removing two amino groups from an aromatic diamine. Here, the aromatic diamine refers to a compound having two amino groups directly bonded to an aromatic ring. Among them, R ⁵ has 6 carbon atoms selected from a monocyclic aromatic group, a condensed polycyclic aromatic group, and a group in which two or more of these aromatic groups are connected directly or by a connecting group. A divalent aromatic group of ˜50 is more preferable. R ⁵ may be the same or different for each structural unit represented by the general formula (3).

In the general formula (3), the structural unit represented by the general formula (3) is such that at least one of the aromatic rings to which the two amino acids of the aromatic diamine in R ⁵ are bonded is in the meta position. It is more preferable to include a structural unit bonded to the main chain with two bonds located at the position. For example, in the case where the aromatic diamine is phenylenediamine, such a structural unit includes a single benzene ring to which two amino groups are bonded, with two bonds in the meta position as the main chain. Is a structural unit connected to That is, in such a case, the aromatic diamine is m-phenylenediamine, and R5 is a divalent m-phenylene group obtained by removing two amino groups from m-phenylenediamine.

  Further, for example, when the aromatic diamine is diaminodiphenylmethane, at least one of the two benzene rings bonded to each of the two amino groups is mainly a double bond located at the meta position. A structural unit attached to a chain. That is, in such a case, the aromatic diamine is 3,3′- or 3,4′-diaminodiphenylmethane, and R5 represents two amino groups from 3,3′- or 3,4′-diaminodiphenylmethane. Excluded divalent groups.

  Thereby, it becomes possible to reduce imidation temperature, such as a polyamic acid. Specifically, it is possible to obtain a polyamic acid having an imidization rate of 95% or more by heating at 180 ° C. or lower.

  Conventional photosensitive polyimides have been studied mainly for semiconductor applications, and there is no problem with semiconductors even if the temperature of imidization is high. I did not come. Conventional photosensitive polyimide is usually obtained by imidization at a temperature of 300 ° C. or higher after exposure and development in the state of polyamic acid. When such a photosensitive polyimide is used as the FPC photosensitive dry film resist, heat of 250 ° C. or higher is applied to the FPC itself. However, in general, resins having lower heat resistance than polyimide, such as epoxy resin, are used as the constituent material for rigid and flexible printed circuit boards, and have only heat resistance of 200 ° C. or lower. Therefore, when these photosensitive polyimides cured at a high temperature of 300 ° C. or higher are used for FPC applications, the copper foil is oxidized and the crystal structure of the copper is changed due to the high temperature, resulting in a problem that the strength of the copper foil is lowered. . Therefore, such photosensitive polyimide cannot be used for rigid and flexible printed circuit boards.

  By using the above polyamic acid, photosensitive development that can be developed in water, has excellent resolution, flame retardancy, adhesion, moisture resistance, electrical reliability, and low warpage, and also has a low imidization temperature. A film resist can be obtained.

  Therefore, it is possible to produce a printed wiring board by curing such a photosensitive dry film resist at a temperature of 180 ° C. or less to form an insulating protective layer. Thereby, the oxidation of copper foil and the crystal structure change of copper by high temperature occur, the problem that the intensity | strength of copper foil falls is eliminated, and a printed wiring board with sufficient performance can be manufactured.

  When the aromatic ring is bonded to the main chain with two bonds located in the ortho position, the imide ring formed by imidization and the main chain are close to each other. As a result, since steric hindrance occurs, imidization is inhibited. Therefore, it is considered that the imidization temperature tends to increase.

  On the other hand, when the aromatic ring is bonded to the main chain with two bonds located at the para position, steric hindrance does not occur, but the entire main chain becomes linear and receives thermal vibration. It becomes difficult to increase the glass transition temperature (Tg). Moreover, it is thought that Tg becomes high also when the whole principal chain becomes linear and the cohesive force between molecules increases. That is, during imidization, water molecules are removed and the ring is closed, so that the volume is reduced. However, imidation cannot be performed unless the whole molecule moves.

  In addition, when the aromatic ring is bonded to the main chain with two bonds located at the meta position, light absorption tends to be small. It can be a resin.

Therefore, the structural unit represented by the general formula (3) is a structural unit in which the aromatic ring in R ⁵ is bonded to the main chain with two bonds in the ortho position or the para position. It may be included as long as it does not affect the increase in the conversion temperature or Tg, but it is preferably included at a lower rate.

  In other words, the structural unit represented by the general formula (3) includes a higher proportion of the structural unit in which the aromatic ring is bonded to the main chain with two bonds located at the meta position. preferable.

  For example, {(number of moles of amino group of meta position in aromatic diamine) / (number of moles of amino group of total aromatic diamine used for production of polyamic acid precursor)} × 100 = content of meta position (%) Then, the content of the meta position is more preferably 60% or more, and further preferably 80% or more. In addition, the number of moles of the amino group of the wholly aromatic diamine is obtained by doubling the number of moles of the wholly aromatic diamine used for the production of the polyamic acid. For example, when only 3,3′-diphenyl ether is used as the aromatic diamine used for producing the polyamic acid precursor, the content of the meta position is 100%, and when only 3,4′-diphenyl ether is used. The meta-position content is 50%, and when only 4,4′-diphenyl ether is used, the meta-position content is 0%. Moreover, when only m-phenylenediamine is used as the aromatic diamine used in the production of the polyamic acid, the content of the meta position is 100%, and only p-phenylenediamine or o-phenylenediamine is used. The content of the meta position is 0%.

  Moreover, {(mole number of para-position amino group in aromatic diamine) / (mole number of amino group of total aromatic diamine used for production of polyamic acid precursor)} × 100 = content of para-position (%) Then, the para-position content is more preferably 20% or less.

The aromatic diamine having a meta-position amino group is particularly limited as long as it is a diamino compound in which an amino group is directly bonded to an aromatic ring and the amino group is located at 3- or m-. However, specific examples include, for example, m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3 ′. -Diaminodiphenylsulfone, 3,3'-diaminobenzanilide, 2,2-bis (3-aminophenyl) hexafluoropropane, 3,3'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2, , 2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] sulfur 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) -biphenyl 1,3-bis (3-aminophenoxy) benzene, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis (3-aminophenyl) propane, 9,9-bis (3 -Aminophenyl) fluorene, 4,4 '-(m-phenyleneisopropylidene) bisaniline, 4,6-diaminoresorcinol, 3,3'-diamino-4,4'-dihydroxybiphenyl, 3,3'-diamino-4 , 4′-dihydroxydiphenylmethane, 2,2-bis [3-amino-4-hydroxyphenyl] propane, 2,2-bis [3-amino-4-hydride Xylphenyl] hexafluoropropane, 3,3′-diamino-4,4′-dihydroxydiphenyl ether, 3,3′-diamino-4,4′-dihydroxydiphenylsulfone, bis [4- (3-amino-4-hydroxyphenoxy) ) Bis [(hydroxyphenoxy) phenyl] sulfone such as phenyl] sulfone, 3,3′-diamino-4,4′-dihydroxybiphenyl, 2,2′-bis [3-amino-4-hydroxyphenyl] propane, 3 , 3'-diamino-4,4'-dicarboxybiphenyl, 3,3'-diamino-4,4'-dicarboxydiphenylmethane, 2,2-bis [3-amino-4-carboxyphenyl] propane, 2, 2-bis [3-amino-4-carboxyphenyl] hexafluoropropane, 3,3′-diamino-4,4 ′ Dicarboxydiphenyl ether, 3,3'-diamino-4,4'-dicarboxylate diphenyl sulfone, can be exemplified diamine compounds such as 3,5-diaminobenzoic acid. In such a case, the structural unit represented by the general formula (3) has a structure in which R ⁵ in the general formula (3) excludes two amino groups of the aromatic diamine.

  In particular, in order to obtain a polyamic acid having high electrical reliability, it is more desirable to select a compound having no hydroxyl group or carboxyl group among the aromatic diamines having a meta-position amino group as exemplified above.

  The aromatic diamine having a meta-position amino group includes m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, and 3,3′-diaminodiphenylsulfone. 3,3′-diaminobenzanilide, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4 -(3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (3-aminophenoxy) benzene, 4,4'-bis (3-aminophenoxy) -biphenyl, 1,3-bis (3-aminophenoxy) benzene, bis [ - and more preferably a (3-aminophenoxy) phenyl] sulfone or 2,2-bis (3-aminophenyl) propane.

  Moreover, in addition to the structural unit represented by the said General formula (2) and the structural unit represented by the said General formula (3), the polyamic acid used as a binder polymer further has the following general formula ( 4)

(Wherein R ⁶ represents a tetravalent organic group, and R ⁷ represents the following chemical formulas a, b, c, d, e, f or g:

In the chemical formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in the chemical formula f, R ⁸ represents a hydrogen atom or a methyl group. Represents an ethyl group or a butyl group. )
You may have the structural unit represented by these.

In general formula (4), R ⁶ is not particularly limited as long as it is a tetravalent organic group, but it is not limited to a monocyclic aromatic group, a condensed polycyclic aromatic group, and aromatics thereof. It is more preferable that two or more of the groups are tetravalent aromatic groups having 6 to 50 carbon atoms selected from groups linked directly or by a linking group. Specific examples of R ⁶ include a residue obtained by removing two —CO—O—CO— from an acid dianhydride described later. R ⁶ may be the same or different for each structural unit represented by the general formula (4).

  By further having the structural unit represented by the general formula (4), an improvement in compatibility with the (meth) acrylic compound can be expected.

In the polyamic acid composed of the structural unit represented by the general formula (2), the structural unit represented by the general formula (3), and, in some cases, the structural unit represented by the general formula (4), The structural unit represented by the molar fraction of the structural unit represented by the general formula (2) and the structural unit represented by the general formula (4) with respect to the entire structural unit in the polyamide acid as the binder polymer or (A) the binder polymer. Total mole fraction of:
((Number of moles of structural unit represented by general formula (2)) + (number of moles of structural unit represented by general formula (4))) ÷ (mol of structural unit represented by general formula (2) Number + number of moles of structural unit represented by general formula (3) + number of moles of structural unit represented by general formula (4)) × 100
Is preferably 10% or more and less than 90%, more preferably 20% or more and less than 80%, further preferably 30% or more and less than 70%, and more preferably 40% or more and less than 60%. Particularly preferred. When the sum of the molar fractions of the structural unit represented by the general formula (2) and the structural unit represented by the general formula (4) is 10% or more, the temperature is lower than that of a conventional polyamic acid or the like. It is possible to obtain a polyamic acid or the like which can be imidized and has low warpage and excellent flexibility and flexibility.

At this time, the structural unit represented by the general formula (2) with respect to the sum of the molar fraction of the structural unit represented by the general formula (2) and the molar fraction of the structural unit represented by the general formula (4) Mole fraction of:
(Number of moles of structural unit represented by general formula (2)) ÷ (number of moles of structural unit represented by general formula (2) + number of moles of structural unit represented by general formula (4)) × 100
May be larger than 0 and 100% or less, more preferably 10% or more and 100% or less, and still more preferably 30% or more and 100% or less. This is preferable because high flame retardancy, flexibility and flexibility can be exhibited.

  The weight average molecular weight of the polyamic acid containing at least the structural units (2) and (3) and (4) depending on the case is preferably 2000 or more and 1000000 or less, and more preferably 5000 or more and 300000 or less. If the weight average molecular weight of the polyamic acid is less than 2000, the molecular weight of the resulting polyimide tends to be low and the strength tends to decrease, which may be undesirable. If it exceeds 1,000,000, the development time of the photosensitive resin tends to be long. Therefore, it may not be preferable.

  The weight average molecular weight / number average molecular weight of the polyamic acid containing at least the structural units (2) and (3), and optionally (4) is preferably 2 or more and 10 or less, and preferably 2 or more and 5 or less. It is more preferable.

  When at least one of the first photosensitive layer and the second photosensitive layer, more preferably the first photosensitive layer contains the polyamic acid, flame retardancy, moisture resistance, electrical reliability, and low warpage are achieved. The effect that it is excellent and can provide the photosensitive dry film resist which has a low imidation temperature can be acquired.

  Of course, the binder polymer, in addition to the polyamic acid containing at least the structural units (2) and (3), and optionally (4), as long as it does not adversely affect the performance of the resulting photosensitive dry film resist, Other polyamic acids may be included.

  The polyamic acid is represented by the polyamic acid composed of the structural unit represented by the general formula (2) and the structural unit represented by the general formula (3), and the general formula (4). The mixture of the polyamic acid which consists of a structural unit and the structural unit represented by the said General formula (3) may be sufficient. In such a case as well, in the case of a copolymer comprising the structural unit represented by (2), the structural unit represented by the general formula (3), and the structural unit represented by the general formula (4) Similar effects can be obtained.

  In the photosensitive dry film resist according to the present invention, (A) the binder polymer is composed of the structural unit represented by the above general formula (2), the structural unit represented by the above general formula (3), and the case. The polyamic acid is preferably composed of a structural unit represented by the general formula (4), but the (A) binder polymer has the following general formula (4).

(Wherein R ⁶ represents a tetravalent organic group, and R ⁷ represents the following chemical formulas a, b, c, d, e, f or g:

In the chemical formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in the chemical formula f, R ⁸ represents a hydrogen atom or a methyl group. Represents an ethyl group or a butyl group. )
A structural unit represented by
The following general formula (3)

(In the formula, R ⁴ represents a tetravalent organic group, and R ⁵ represents a divalent organic group obtained by removing two amino groups from an aromatic diamine.)
It may consist of a structural unit represented by

  Here, regarding the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4), the structural unit represented by the general formula (2) and the general formula (3 ) And, in some cases, as described for the polyamic acid composed of the structural unit represented by the general formula (4), description thereof is omitted here.

The polyamic acid composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4) is represented by the general formula (4) with respect to the entire structural unit in the polyamic acid. Mole fraction of structural units:
(Number of moles of structural unit represented by general formula (4)) ÷ (number of moles of structural unit represented by general formula (3) + number of moles of structural unit represented by general formula (4)) × 100
Is preferably 10% or more and less than 90%, more preferably 20% or more and less than 80%, further preferably 30% or more and less than 70%, and more preferably 40% or more and less than 60%. Particularly preferred. When the molar fraction of the structural unit represented by the general formula (4) is 10% or more, imidization at a temperature lower than that of conventional polyamic acid or the like is possible, and warpage is small and flexible. A polyamic acid having excellent flexibility can be obtained.

  The weight average molecular weight of the polyamic acid composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4) is preferably 2,000 or more and 1,000,000 or less. More preferably, it is 300,000 or less. If the weight average molecular weight of the polyamic acid is less than 2,000, the resulting polyimide has a low molecular weight and tends to decrease the strength, and if it exceeds 1,000,000, the development time of the photosensitive resin tends to be long. .

  The weight average molecular weight / number average molecular weight of the polyamic acid composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4) is 2 or more and 10 or less. It is preferable that it is 2 or more and 5 or less.

  A polyamide in which at least one of the first photosensitive layer and the second photosensitive layer, more preferably both, is composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4). In the case of containing an acid, it is possible to provide a photosensitive dry film resist having excellent flame retardancy, moisture resistance, electrical reliability, and low warpage, and having a low imidization temperature. An effect can be obtained.

  Note that at least one of the first photosensitive layer and the second photosensitive layer may contain other polyamic acid as long as it does not adversely affect the performance of the resulting photosensitive dry film resist.

  As the polyamic acid used as the binder polymer of the second photosensitive layer, it is preferable to use the polyamic acid used in the first photosensitive layer, but other polyamic acids can be used.

  As the polyamic acid used as the binder polymer of the second photosensitive layer, the structural unit represented by the above general formula (2), the structural unit represented by the above general formula (3), and the above general formula ( The polyamic acid composed of the structural unit represented by 4) and the polyamic acid composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4) can be used. In addition, for example, a polyamic acid composed of a structural unit represented by the general formula (3) can be suitably used.

  The production method of the polyamic acid used in the present invention is not particularly limited as long as it has the above-described configuration. For example, the structural unit represented by the above general formula (2) and the above general formula The polyamic acid comprising the structural unit represented by (3) is an acid dianhydride, an aromatic diamine, and the following general formula (5)

(In the formula, each R ² independently represents an alkylene group having 2 to 5 carbon atoms, each R ³ independently represents a methyl group or a phenyl group, and the content of the phenyl group in R ³ is 15) % To 40%, and m is an integer of 4 to 20.)
It can manufacture by making the polysiloxane diamine represented by these react in an organic polar solvent.

  Further, for example, the polyamic acid composed of the structural unit represented by the general formula (2), the structural unit represented by the general formula (3), and the structural unit represented by the general formula (4) is , Acid dianhydride, aromatic diamine, polysiloxane diamine represented by the above general formula (5), and a ′, b ′, c ′, d ′, e ′, f ′ represented by the following chemical formula group (6) Or g '

(In the chemical formula a ′, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in the chemical formula f ′, R ⁸ represents a hydrogen atom, a methyl group, an ethyl group, or a butyl group. Is shown.)
Can be produced by reacting in an organic polar solvent.

  Further, for example, the polyamic acid composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4) is an acid dianhydride, an aromatic diamine, and the chemical formula group ( It can be produced by reacting a ′, b ′, c ′, d ′, e ′, f ′ or g ′ shown in 6) in an organic polar solvent.

  In addition, when using a ', b', c ', d', e ', f', or g 'shown by the said Chemical formula group (6), these may be used independently and two or more types are used. You may combine.

  For example, the polyamic acid which consists of a structural unit represented by the said General formula (4) can be manufactured by making an acid dianhydride and aromatic diamine react in an organic polar solvent.

In the general formula (5), each R ² is independently an alkylene group having 2 to 5 carbon atoms, specifically an ethylene group, a propylene group, a tetramethylene group, or a pentamethylene group.

In general formula (5), each R ³ independently represents a methyl group or a phenyl group. Here, the content of the phenyl group in R ^3, the content of methyl groups, will not be described here are the same as those of R ₃ in the general formula (2) in which is described above.

In the general formula (5), the methyl group in R ³ may be partially substituted with an ethyl group or a propyl group unless it adversely affects the performance of the resulting photosensitive resin composition. Good.

  In addition, the number of repeating units m of the siloxane bond in the general formula (5) is the same as m in the general formula (2) described above, and thus the description thereof is omitted here.

The acid dianhydride is not particularly limited, and any acid dianhydride can be used. In addition, the residue remove | excluding two -CO-O-CO- from this acid dianhydride is a suitable example of R < ¹ > in General formula (2), said R < ⁴ >, and R < ⁶ >. Specific examples of the acid dianhydride include 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride. 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 2,2′-hexafluoropropylidenediphthalic dianhydride, 2,2-bis (4-hydroxyphenyl) propanedi Benzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, pyromellitic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7- Naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1, 2,3,4-furan Tetracarboxylic 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′-perfluoroisopropylidenediphthalic 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′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, etc. Aromatic tetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, butanetetracarboxylic dianhydride 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbonane-2-acetic acid dianhydride 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [ Examples include aliphatic or alicyclic tetracarboxylic dianhydrides such as 2,2,2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride. These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

  Especially, as said acid dianhydride, it is more preferable to use aromatic tetracarboxylic dianhydride from the point that the flame retardance of the polyimide obtained is excellent.

  In order to obtain a polyimide having high solubility in an organic solvent, 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride, 2,2′-hexafluoropropylidenediphthalic dianhydride 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 4,4- (4,4′-isopropylidenediphenoxy) bisphthalic anhydride, 2,2-bis (4-hydroxyphenyl) ) Propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4 ′ -Tetraphenylsilane tetracarboxylic dianhydride or 1,2-ethanedibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride as the acid dianhydride, Including More preferably, it is present.

  Furthermore, from the point of being industrially inexpensive, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 2,2′-hexafluoropropylidenediphthalic dianhydride, 2,2-bis (4-hydroxyphenyl) propanedibenzoate- 3,3 ′, 4,4′-tetracarboxylic dianhydride and pyromellitic dianhydride are preferably used.

  The aromatic diamine is not particularly limited, and any aromatic diamine can be used. The aromatic diamine is not particularly limited, and examples thereof include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, and 4,4′-. Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl 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, 3,5-diamino-3'-to Fluoromethylbenzanilide, 3,5-diamino-4′-trifluoromethylbenzanilide, 3,4′-diaminodiphenyl ether, 2,7-diaminofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl ] Propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) -biphenyl 4,4′-bis (3-aminophenoxy) -biphenyl, 1,3′-bis (4-aminophenoxy) benze 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) fluorene, 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenylene) Isopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-bis [4- (4-amino-2-trifluoro) Methyl) phenoxy] -aromatic diamine such as octafluorobiphenyl; aromatic diamine 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; Diaminoresorcinols such as 4,6-diaminoresorcinol; 3,3′-diamino-4,4′-dihydroxy Biphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, 4,4′-diamino-2,2′-dihydroxybiphenyl, 4,4′-diamino-2,2 ′, 5,5′-tetra Hydroxybiphenyl compounds such as hydroxybiphenyl; 3,3′-diamino-4,4′-dihydroxydiphenylmethane, 2,2-bis [3-amino-4-hydroxyphenyl] propane, 2,2-bis [4-amino -3-hydroxyphenyl] propane, 2,2-bis [3-amino-4-hydroxyphenyl] hexafluoropropane, hydroxy such as 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenylmethane Diphenylmethanes or hydroxydiphenylalkanes; 3,3′-diamino-4,4′-dihydroxydipheny Ether, 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 4,4′-diamino-2,2′-dihydroxydiphenyl ether, 4,4′-diamino-2,2 ′, 5,5′-tetra Hydroxydiphenyl ether compounds such as hydroxydiphenyl ether; 3,3′-diamino-4,4′-dihydroxydiphenyl sulfone, 4,4′-diamino-3,3′-dihydroxydiphenyl sulfone, 4,4′-diamino-2,2 Diphenylsulfone compounds such as '-dihydroxydiphenylsulfone, 4,4'-diamino-2,2', 5,5'-tetrahydroxydiphenylsulfone; 2,2-bis [4- (4-amino-3-hydroxyphenoxy) ) Bis [(hydroxyphenoxy) pheny such as phenyl] propane Alkane compounds; bis [(hydroxyphenoxy) phenyl] such as bis [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone and bis [4- (3-amino-4-hydroxyphenoxy) phenyl] sulfone Sulfone compounds; diaminophenols such as 2,4-diaminophenol; 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxydiphenylmethane, 4,4 ′ -Diamino-2,2'-dihydroxydiphenylmethane, 2,2'-bis [3-amino-4-hydroxyphenyl] propane, 4,4'-bis (4-amino-3-hydroxyphenoxy) biphenyl, etc. Bis (hydroxyphenoxy) biphenyl compounds; diamino such as 2,5-diaminoterephthalic acid 3,3′-diamino-4,4′-dicarboxybiphenyl, 4,4′-diamino-3,3′-dicarboxybiphenyl, 4,4′-diamino-2,2′-dicarboxybiphenyl; Carboxybiphenyl compounds such as 4,4′-diamino-2,2 ′, 5,5′-tetracarboxybiphenyl; 3,3′-diamino-4,4′-dicarboxydiphenylmethane, 2,2-bis [ 3-amino-4-carboxyphenyl] propane, 2,2-bis [4-amino-3-carboxyphenyl] propane, 2,2-bis [3-amino-4-carboxyphenyl] hexafluoropropane, and 4, Carboxydiphenylalkanes such as 4′-diamino-2,2 ′, 5,5′-tetracarboxydiphenylmethane; 3,3′-diamino-4, '-Dicarboxydiphenyl ether, 4,4'-diamino-3,3'-dicarboxydiphenyl ether, 4,4'-diamino-2,2'-dicarboxydiphenyl ether, 4,4'-diamino-2,2', Carboxydiphenyl ether compounds such as 5,5′-tetracarboxydiphenyl ether; 3,3′-diamino-4,4′-dicarboxydiphenyl sulfone, 4,4′-diamino-3,3′-dicarboxydiphenyl sulfone, 4, Diphenyl sulfone compounds such as 4′-diamino-2,2′-dicarboxydiphenyl sulfone and 4,4′-diamino-2,2 ′, 5,5′-tetracarboxydiphenyl sulfone; 2,2-bis [4- Bis [(calcium (4-amino-3-carboxyphenoxy) phenyl] propane and the like Boxyphenoxy) phenyl] alkane compounds; bis [(carboxyphenoxy) phenyl] sulfone compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone; 3,5-diaminobenzoic acid Examples include diaminobenzoic acids such as acids. These aromatic diamines can be used alone or in combination of two or more.

  Among them, as described above, the aromatic diamine is bonded to the main chain with two bonds located at the meta position, at least one of the aromatic rings to which the two amino groups of the aromatic diamine are bonded. The aromatic diamine is more preferably an aromatic diamine having a meta-position amino group as exemplified above. Thereby, it is possible to reduce the imidization temperature of the polyamic acid precursor or the like. Moreover, the aromatic diamine which has a meta position amino group can also be used individually or in combination of 2 or more types.

  The order in which the acid dianhydride, the aromatic diamine, the polysiloxane diamine or the diamine of the chemical formula group (6) is reacted in an organic polar solvent is not particularly limited. Group diamine may be reacted with polysiloxane diamine or diamine of formula group (6) simultaneously, or after the reaction of acid dianhydride with polysiloxane diamine or diamine of formula group (6) is started first. An aromatic diamine may be added to cause the reaction, or after the reaction between the acid dianhydride and the aromatic diamine is first started, the polysiloxane diamine or the diamine of the chemical formula group (6) may be added to cause the reaction.

  Among them, it is more preferable to react the acid dianhydride with the polysiloxane diamine or the diamine of the chemical formula group (6) first, and then add the aromatic diamine to cause the reaction.

  In such a case, first, an acid dianhydride and a polysiloxane diamine or a diamine of the chemical formula group (6) may be reacted in an organic polar solvent, for example, consisting of an acid dianhydride and an organic polar solvent. A polysiloxane diamine, a diamine of the chemical formula group (6) or a solution thereof may be added to the solution or the suspension solution. Subsequently, the polyimide precursor (polyamic acid) used in the present invention can be synthesized by adding an aromatic diamine.

  The order of reacting the acid dianhydride, aromatic diamine, polysiloxane diamine and diamine of the chemical formula group (6) in an organic polar solvent is not particularly limited, and the acid dianhydride, aromatic diamine is not limited. The polysiloxane diamine and the diamine of the chemical formula group (6) may be reacted simultaneously. Moreover, after starting reaction of an acid dianhydride and polysiloxane diamine, you may make it react with the diamine of Chemical formula group (6), and add aromatic diamine after that, and you may make it react. Moreover, after starting reaction of an acid dianhydride and aromatic diamine first, you may make it react with polysiloxane diamine and then add and react diamine of Chemical formula group (6).

  The organic polar solvent is not particularly limited. For example, dimethyl sulfoxide, N, N′-dimethylformamide, N, N′-diethylformamide, N, N′-dimethylacetamide, N, N′— Examples include diethylacetamide, N-methylpyrrolidone, hexamethylphosphoric triamide, dioxolane, tetrahydrofuran, 1,4-dioxane, acetonitrile and the like, and these can be used alone or in admixture of two or more.

  At this time, the reaction between the acid dianhydride and the polysiloxane diamine and / or the diamine of the chemical formula group (6) is preferably performed in the organic polar solvent under a temperature condition of −20 ° C. or more and 80 ° C. or less. It is more preferable to make it react on temperature conditions of -15 degreeC or more and 50 degrees C or less. By setting the reaction temperature to −20 ° C. or higher, the acid dianhydride and the polysiloxane diamine and / or the diamine of the chemical formula group (6) can be reacted. In addition, the reaction time when the acid dianhydride is reacted with the polysiloxane diamine and / or the diamine of the chemical formula group (6) is not particularly limited, but is preferably, for example, 1 to 12 hours. .

  At this time, the number of moles of acid dianhydride to be reacted is preferably larger than the number of moles of polysiloxane diamine and / or diamine of chemical formula group (6). Thereby, the polyimide precursor (polyamic acid) oligomer of an acid dianhydride terminal can be obtained.

  Subsequently, the reaction temperature when the aromatic diamine is added to the reaction is preferably −20 ° C. or higher and 80 ° C. or lower, and more preferably −15 ° C. or higher and 50 ° C. or lower. By setting it as this temperature range, a copolymerization with aromatic diamine can be performed suitably. Also, the reaction time when the aromatic diamine is added and reacted is not particularly limited, but is preferably 0.5 hours to 24 hours, for example.

  When the aromatic diamine exceeds 90 mol% of the total diamine, the imidization temperature tends to be increased, and therefore 90 mol% or less is preferable, and 80 mol% or less is more preferable.

  In the polyamic acid of the present invention, the logarithmic viscosity at 30 ° C. of a solution of 5 g / l N-methylpyrrolidone is preferably in the range of 0.2 to 4.0, and in the range of 0.3 to 2.0. More preferably.

(I-2-3) Soluble polyimide having carboxyl group and / or hydroxyl group From the viewpoint of flame retardancy and heat resistance, it is also preferable to use a soluble polyimide having a carboxyl group and / or hydroxyl group as a binder polymer. Furthermore, since it has already been imidized, it is possible to set the temperature of the heat curing low or to set the time short, and thus the productivity is excellent.

  The soluble polyimide is not particularly limited as long as it is a polyimide that dissolves in an organic solvent. In the present invention, a soluble polyimide that exhibits a solubility of 1.0 g or more at 20 ° C. with respect to 100 g of the organic solvent is preferable. More preferably, it exhibits a solubility of 5.0 g or more at 20 ° C., and more preferably a solubility of 10 g or more at 20 ° C. If the solubility at 20 ° C. in 100 g of an organic solvent is less than 1.0 g, it tends to be difficult to form a photosensitive dry film resist at a desired thickness. The organic solvent is not particularly limited, but includes formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, ether solvents such as 1,4-dioxane, 1,3-dioxolane, and tetrahydrofuran. Can be mentioned.

  The weight average molecular weight of the soluble polyimide having a carboxyl group and / or a hydroxyl group is not particularly limited, but is preferably 5,000 to 300,000, and more preferably 10,000 to 200,000. If the weight average molecular weight is less than 5,000, the photosensitive dry film resist produced using the photosensitive resin composition of the present invention tends to be sticky, and the cured film tends to have poor flex resistance. . On the other hand, if the weight average molecular weight is greater than 200,000, the solution viscosity of the soluble polyimide having a carboxyl group and / or hydroxyl group tends to be too high, and the handling tends to be difficult, and the developability of the produced photosensitive dry film resist is lowered. There is a case. The weight average molecular weight can be measured by size exclusion chromatography (SEC), for example, HLC8220GPC manufactured by Tosoh Corporation.

  The weight average molecular weight (hereinafter referred to as acid equivalent) per carboxyl group and / or hydroxyl group in the soluble polyimide having a carboxyl group and / or hydroxyl group is preferably 7000 or less, more preferably 5000 or less. Preferably, it is 3000 or less. If the acid equivalent exceeds 7000, aqueous development of the photosensitive dry film resist produced using the photosensitive resin composition of the present invention tends to be difficult. In addition, the acid equivalent of the said soluble polyimide can be calculated | required by calculating from the composition of the soluble polyimide which has a carboxyl group and / or a hydroxyl group.

<Production method of polyimide>
Hereinafter, in order to explain the method for producing a soluble polyimide having a carboxyl group and / or a hydroxyl group, a method for synthesizing a polyamic acid and a method for dehydrating and ring-closing the polyamic acid to imidize will be described in detail.

<Synthesis of polyamic acid>
The soluble polyimide having a carboxyl group and / or a hydroxyl group can be obtained from a polyamic acid that is a precursor thereof. This polyamic acid can be obtained by reacting diamine and acid dianhydride in an organic solvent. Specifically, in an inert atmosphere such as argon or nitrogen, the diamine is dissolved in an organic solvent or dispersed in a slurry to obtain a diamine solution. On the other hand, the acid dianhydride may be added to the diamine solution after being dissolved or dispersed in an organic solvent or in a solid state.

  Although it does not specifically limit as diamine used in order to synthesize | combine the polyamic acid which is the precursor of the soluble polyimide which has a carboxyl group and / or a hydroxyl group of this invention, From the point of aqueous | water-based developability, it is in 1 molecule. It is preferable to use a diamine having one or more carboxyl groups and / or hydroxyl groups as at least a part of the raw material. In view of heat resistance and chemical resistance, it is preferable to use an aromatic diamine having one or more aromatic rings in one molecule as at least a part of the raw material. In particular, if an aromatic diamine having one or more carboxyl groups and / or hydroxyl groups in one molecule is used as a part of the raw material, heat resistance and aqueous developability can be imparted to the resulting photosensitive dry film resist. This is particularly preferable because it can be performed.

  The aromatic diamine having a carboxyl group and / or a hydroxyl group is not particularly limited, but the following general formula (7)

(In the formula, R ¹⁵ may be the same or different, and is either a carboxyl group or a hydroxyl group, and R ¹⁶ and R ¹⁷ may be the same or different, An alkyl group having 1 to 9 carbon atoms, an alkoxy group having 2 to 10 carbon atoms, or —COOR ¹⁸ (R ¹⁸ represents an alkyl group having 1 to 9 carbon atoms), and X may be the same or different; _{-O -, - S -, -} SO 2 -, - C (CH 3) 2 -, - CH 2 -, - C (CH 3) (C 2 H 5) -, or -C _{(CF 3) 2} - M is an integer greater than or equal to 1, n is an integer greater than or equal to 0, and m and n are integers that satisfy the condition of m + n = 4, p is an integer greater than or equal to 1, q is an integer greater than or equal to 0, q is an integer satisfying the condition of p + q = 4, and r is an integer of 0 to 10.) It is preferable to use the system diamine as part of the soluble polyimide material.

  The aromatic diamine having a carboxyl group is not particularly limited, and examples thereof include diaminobenzoic acid such as 3,5-diaminobenzoic acid and 3,3′-diamino-4,4′-dicarboxybiphenyl. Carboxybiphenyl compounds such as 4,4′-diamino-2,2 ′, 5,5′-tetracarboxybiphenyl, 4,4′-diamino-3,3′-dicarboxydiphenylmethane, 3,3′-diamino Carboxydiphenylalkanes such as 4,4′-dicarboxydiphenylmethane, carboxydiphenyl ether compounds such as 4,4′-diamino-2,2 ′, 5,5′-tetracarboxydiphenyl ether, 3,3′-diamino-4 Diphenylsulfone compounds such as 2,4′-dicarboxydiphenylsulfone, 2,2-bis [4- (4-amino-3-carbohydrate) Bis (carboxyphenoxy) biphenyl compounds such as ciphenoxy) phenyl] propane, bis [(carboxyphenoxy) phenyl] sulfone compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone, etc. Can be illustrated.

  Among these, a part of the structural formula of the particularly preferred carboxyl group-containing aromatic diamine is shown below.

Next, the aromatic diamine having a hydroxyl group is not particularly limited. For example, 2,2′-diaminobisphenol A, 2,2′-bis (3-amino-4-hydroxyphenyl) hexa Fluoropropane, bis (2-hydroxy-3-amino-5-methylphenyl) methane, 2,6-di [(2-hydroxy-3-amino-5-methylphenyl) methyl] -4-methylphenol, 2, Mention may be made of compounds such as 6-di [(2-hydroxy-3-amino-5-methylphenyl) methyl] -4-hydroxybenzoate.

  Among these, some of the structural formulas of particularly preferred hydroxyl group-containing aromatic diamines are shown below.

By using these diamines as a part of the raw material, the acid equivalent of the soluble polyimide containing a carboxyl group and / or a hydroxyl group to be obtained is lowered, and the aqueous developability can be improved.

  Needless to say, in addition to the diamine having a carboxyl group and / or a hydroxyl group, other known diamines may be used simultaneously as part of the raw material of the soluble polyimide. Examples thereof include bis [4- (3-aminophenoxy) phenyl] sulfone, [bis (4-amino-3-carboxy) phenyl] methane, polysiloxane diamine represented by the general formula (1), and the like. In particular, the polysiloxane diamine represented by the general formula (1) is particularly preferable because it can improve flexibility, adhesion, and flexibility. The said diamine can be used individually or in combination of 2 or more types.

(In the formula, each R ₁ independently represents a hydrocarbon having 1 to 5 carbon atoms, each R ₂ independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, n represents an integer of 1 to 20.)
On the other hand, the acid dianhydride used for synthesizing the polyamic acid is not particularly limited, but from the viewpoint of improving heat resistance, an acid dianhydride having 1 to 4 aromatic rings or an alicyclic acid diacid. It is preferable to use an anhydride. In order to obtain a polyimide resin having high solubility in an organic solvent, it is preferable to use at least a part of an acid dianhydride having two or more aromatic rings, and an acid dianhydride having four or more aromatic rings. More preferably, it is used as at least a part.

  Examples of the acid dianhydride include aliphatic or alicyclic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, Merit acid dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 2,2-bis (hydroxy Phenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, 2,3 ′, 3,4′-biphenyl ether tetracarboxylic dianhydride, 3,4,3 ′ , 4′-biphenyl ether tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydrides such as biphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-2 5-dioxo-3-furanyl - naphtho and aliphatic tetracarboxylic dianhydride having an aromatic ring such as [1,2-c] furan-1,3-dione. The above acid dianhydrides can be used alone or in combination of two or more.

  Among the acid dianhydrides, 2,2-bis (hydroxyphenyl) propanedibenzoate-3,3 ′, 4,4 is used from the viewpoint of ease of synthesis and solubility of the resulting polyimide in an organic solvent. '-Tetracarboxylic dianhydride, 2,3', 3,4'-biphenyl ether tetracarboxylic dianhydride, 3,4,3 ', 4'-biphenyl ether tetracarboxylic dianhydride, biphenyl-3 It is preferable to use at least a part of an acid dianhydride having two or more aromatic rings such as, 4,3 ′, 4′-tetracarboxylic dianhydride.

  When synthesizing polyamic acid using the diamine and acid dianhydride, the reaction may be performed using at least one of each of the diamine and acid dianhydride. That is, for example, by performing a polymerization reaction in an organic solvent using a diamine component containing at least a diamine containing a carboxyl group and / or a hydroxyl group and the acid dianhydride as described above, A polyamic acid containing at least one carboxyl group and / or hydroxyl group in the molecular chain can be obtained.

  At this time, if 1 type of diamine and 1 type of acid dianhydride are substantially equimolar, it will become a polyamic acid of 1 type of acid dianhydride components and 1 type of diamine components. Further, when two or more kinds of acid dianhydride components and two or more kinds of diamine components are used, the molar ratio of the total amount of plural diamine components and the molar ratio of the total amount of plural acid dianhydride components are substantially equimolar. If adjusted, a polyamic acid copolymer can be optionally obtained.

  The temperature condition for the reaction between the diamine and the acid dianhydride (polyamic acid synthesis reaction) is not particularly limited, but is preferably −20 ° C. or higher and 80 ° C. or lower, and preferably −15 ° C. or higher and 50 ° C. or lower. More preferred. If it exceeds 80 ° C., the polyamic acid may be decomposed. Conversely, if it is −20 ° C. or lower, the progress of the polymerization reaction may be slow. Moreover, what is necessary is just to set reaction time arbitrarily in the range of 10 minutes-30 hours.

  Furthermore, the organic solvent used for the synthesis reaction of the polyamic acid is not particularly limited as long as it is an organic polar solvent. However, as the reaction between the diamine and the acid dianhydride proceeds, polyamic acid is generated, and the viscosity of the reaction solution increases. Moreover, as will be described later, the polyamic acid solution obtained by synthesizing the polyamic acid can be heated under reduced pressure to simultaneously remove the organic solvent and imidize. Therefore, as the organic solvent, it is advantageous in terms of the process to select an organic solvent that can dissolve the polyamic acid and has a low boiling point as much as possible.

  Specifically, examples of the organic solvent used in the polyamic acid synthesis reaction include a formamide solvent such as N, N-dimethylformamide, an acetamide solvent such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like. Examples thereof include pyrrolidone solvents such as N-vinyl-2-pyrrolidone and ether solvents such as tetrahydrofuran, dioxane and dioxolane.

<Imidization of polyamic acid>
Next, a method for imidizing the polyamic acid to obtain a polyimide using the polyamic acid will be described. The imidization is performed by dehydrating and ring-closing the polyamic acid. This dehydration ring closure can be performed by an azeotropic method using an azeotropic solvent, a thermal method, or a chemical method.

  In the azeotropic method using an azeotropic solvent, a solvent that azeotropes with water such as toluene and xylene is added to the polyamic acid solution, and the temperature is raised to 170 to 200 ° C. to actively generate water generated by dehydration ring closure. The reaction may be carried out for about 1 to 5 hours while removing from the system. After completion of the reaction, it is precipitated in an alcohol solvent such as methanol, washed with an alcohol solvent as necessary, and then dried to obtain a polyimide resin.

  Dehydration ring closure by a thermal method may be performed by heating the polyamic acid solution. Alternatively, the polyamic acid solution may be cast or applied to a film-like support such as a glass plate, a metal plate, or PET (polyethylene terephthalate), and then heat treatment may be performed within a range of 80 ° C to 300 ° C. Furthermore, the polyamic acid solution can be directly dehydrated and ring-closed by placing the polyamic acid solution directly into a container that has been subjected to a release treatment such as coating with a fluororesin, and then drying by heating under reduced pressure. Polyimide can be obtained by dehydration and ring closure of polyamic acid by such a thermal method.

  In addition, although the heating time of each said process changes with the process amount and heating temperature of the polyamic acid solution which performs dehydration ring closure, generally it is performed in the range of 1 minute-5 hours after the processing temperature reaches the maximum temperature. It is preferable.

  On the other hand, dehydration and ring closure by a chemical method may be performed by adding a dehydrating agent and, if necessary, a catalytic amount of a tertiary amine as a catalyst to the polyamic acid solution and performing a heat treatment. Note that this heat treatment refers to the heat treatment performed by the thermal method described above. Thereby, a polyimide can be obtained.

  As the dehydrating agent in the chemical method, acid anhydrides such as acetic anhydride and propionic anhydride are generally used. As the tertiary amine, pyridine, isoquinoline, triethylamine, trimethylamine, imidazole, picoline, or the like may be used.

  In addition, when the soluble polyimide of the present invention has a hydroxyl group, the reaction between the acid anhydride added as a dehydrating agent and the hydroxyl group is considered, so the acid anhydride to be used is stoichiometrically necessary for imidization. A minimum amount is preferred.

(I-3) (Meth) acrylic compound Next, the (meth) acrylic compound as component (B) will be described. By containing the component (B) in the photosensitive resin composition, not only gives good curability, but also lowers the viscoelasticity at the time of thermal processing of the photosensitive dry film resist to be produced, and at the time of thermal lamination Fluidity can be imparted. That is, heat lamination at a relatively low temperature is possible, and circuit irregularities can be embedded.

  In the present invention, the (meth) acrylic compound refers to a compound selected from the group consisting of (meth) acrylic compounds, epoxy (meth) acrylates, polyester (meth) acrylates, urethane (meth) acrylates, and imide (meth) acrylates. . In the present invention, (meth) acryl refers to an acrylic compound and / or a methacrylic compound.

  The said (meth) acrylic-type compound may use only 1 type, and may combine 2 or more types. The total weight of the (meth) acrylic compound contained in the photosensitive resin composition in the present invention is 1 to 400 parts by weight with respect to 100 parts by weight of the binder polymer (A). Preferably, it is used within the range of 3 to 300 parts by weight, more preferably used within the range of 1 to 200 parts by weight, and particularly preferably within the range of 1 to 100 parts by weight.

  When a (meth) acrylic compound exceeding 200 parts by weight is used as the component (B) with respect to 100 parts by weight of the binder polymer as the component (A), stickiness is likely to occur in the resulting photosensitive dry film resist. .

  Although it does not specifically limit to the photosensitive resin composition of this invention as (B) component, In order to improve the crosslinking density by light irradiation, the polyfunctional (meta) which has at least 2 carbon-carbon double bond. It is preferable to use an acrylic compound. Moreover, in order to provide heat resistance to the photosensitive dry film resist obtained, it is preferable to use a compound having at least one aromatic ring and / or heterocyclic ring in one molecule.

  The (meth) acrylic compound having at least one aromatic ring and / or heterocyclic ring and at least two carbon-carbon double bonds in one molecule is not particularly limited. For example, Aronics M-210, M -211B (manufactured by Toagosei), NK ester A-BPE-4, A-BPE-10-, A-BPE-30 and other bisphenol A EO-modified di (meth) acrylate, Aronix M-208 (manufactured by Toagosei), etc. Bisphenol A PO modified (n = 2 to 20) di (meth) acrylate such as bisphenol F EO modified (n = 2 to 20) di (meth) acrylate, Denacol acrylate DA-250 (manufactured by Nagase Kasei) be able to. Furthermore, although an aromatic ring is not included, isocyanuric acid EO-modified diacrylates such as Aronix M-215 and isocyanuric acid EO-modified triacrylates such as Aronix M-315 (manufactured by Toagosei) can be exemplified. The EO modification indicates that it has an ethylene oxide modification site, and the PO modification indicates that it has a propylene oxide modification site.

  In order to control developability, it is preferable to use a (meth) acrylic compound having an alcohol hydroxyl group. These (meth) acrylic compounds having an alcohol hydroxyl group are excellent in compatibility with the base polymer.

  Examples of the (meth) acrylic compound having an alcohol hydroxyl group include pentaerythritol tri (meth) acrylate, V # 2308, V # 2323 (Osaka Organic Chemical Industry), and the like.

  In particular, by using a (meth) acrylic compound containing at least one epoxy group and one (meth) acrylic group in one molecule, the hydrolysis resistance of the resulting photosensitive dry film resist and copper It becomes possible to improve the adhesiveness to foil.

  Although it does not specifically limit as a (meth) acrylic-type compound which contains at least 1 or more epoxy group and 1 or more (meth) acryl group in 1 molecule, For example, glycidyl compounds, such as glycidyl methacrylate, NK oligo EA-1010 EA-6310 (manufactured by Shin-Nakamura Chemical) and the like.

  Moreover, it is preferable to use an epoxy (meth) acrylate containing at least two or more hydroxyl groups in one molecule. By using such an epoxy (meth) acrylate, the solubility of the resulting photosensitive dry film resist in an aqueous developer is improved, and the development time can be shortened.

  Although it does not specifically limit as an epoxy (meth) acrylate which contains at least 2 or more hydroxyl group in 1 molecule, Lipoxy SP-2600 (made by Showa Polymer), NK oligo EA-1020, NK oligo EA-6340 (Shin Nakamura) Chemical)), Karayad R-280, Karayad R-190 (Nippon Kayaku), Ebecryl 600, Ebecryl 3700 (Daicel Cytec), etc. Modified bisphenol A type epoxy acrylate such as LR9019 (BASF), aliphatic epoxy acrylate such as LR8765 (BASF), NK oligo EA- Modifications such as phenol novolac epoxy acrylate such as 6320, NK oligo EA-6340 (manufactured by Shin-Nakamura Chemical), Karayad R-167, MAX-2104 (manufactured by Nippon Kayaku), Denacol acrylate DA-212 (manufactured by Nagase Kasei) , 6-hexanediol diacrylate, modified phthalic acid diacrylate such as Denacol acrylate DA-721 (manufactured by Nagase Kasei), cresol novolac epoxy acrylate such as NK oligo EA-1020 (manufactured by Shin-Nakamura Chemical), etc. it can.

  By using polyester (meth) acrylate, flexibility can be imparted to the produced photosensitive dry film resist. Although it does not specifically limit as polyester (meth) acrylate, For example, Aronix M-5300, M-6100, M-7100 (made by Toagosei) etc. can be mentioned.

  By using urethane (meth) acrylate, flexibility can be imparted to the produced photosensitive dry film resist. Although it does not specifically limit as urethane (meth) acrylate, For example, Aronix M-1100, M-1310 (made by Toagosei), Karayad UX-4101 (made by Nippon Kayaku) etc. can be mentioned.

  By using imide (meth) acrylate, the adhesiveness to the base material (for example, a polyimide film, copper foil, etc.) which bonds the photosensitive dry film resist manufactured can be improved. Although it does not specifically limit as an imide (meth) acrylate, For example, Aronix TO-1534, TO-1429, TO-1428 (made by Toagosei) can be mentioned.

Moreover, as said (meth) acrylic-type compound, bisphenol F EO modified | denatured (n = 2-50) diacrylate, bisphenol A EO modified | denatured (n = 2-50) diacrylate, Sphenol S EO modified | denatured ( n = 2-50) Diacrylate, 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, tetramethylolpropane 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, phenoxy polyethylene glycol Relate, β-acryloyloxyethyl hydrogen succinate, lauryl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 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- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (Methacryloxy / diethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy / polyethoxy) phenyl] propane, polyethylene glycol Coal diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2 -Hydroxy 1-acryloxy 3-methacryloxypropane, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetraacrylate, methoxydipropylene glycol methacrylate, methoxytriethylene glycol acrylate, nonylphenoxy polyethylene glycol acrylate, nonylphenoxy polypropylene Glycol acrylate, 1-acryloyloxypropyl-2-phthalate, isostere Ryl acrylate, polyoxyethylene alkyl ether acrylate, nonylphenoxyethylene glycol acrylate, polypropylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 3-methyl-1,5-pentanediol dimethacrylate, 1,6-methanedi All dimethacrylate, 1,9-nonanediol methacrylate, 2,4-diethyl-1,5-pentanediol dimethacrylate, 1,4-cyclohexanedimethanol dimethacrylate, dipropylene glycol diacrylate, tricyclodecane dimethanol diacrylate 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolypropoxy) phenyl] propane, 2, -Diethyl-1,5-pentanediol diacrylate, ethoxylated tomethylolpropane triacrylate, propoxylated tomethylolpropane triacrylate, isocyanuric acid tri (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, Propoxylated pentathritol tetraacrylate, ditrimethylolpropane tetreacrylate, dipentaerythritol polyacrylate, triallyl isocyanurate, glycidyl methacrylate, glycidyl allyl ether, 1,3,5-triacryloylhexahydro-s-triazine, triallyl 1,3 , 5-Benzenecarboxylate, triallylamine, triallyl citrate, triallyl phosphate, arroba -Vital, diallylamine, diallyldimethylsilane, diallyl disulfide, diallyl ether, zalyl sialate, diallyl isophthalate, diallyl terephthalate, 1,3-dialyloxy-2-propanol, diallyl sulfide diallyl maleate, 4,4'-isopropylidenediphenol Examples include dimethacrylate, 4,4′-isopropylidene diphenol diacrylate, and the like. In order to improve the crosslinking density, it is particularly preferable to use a bifunctional or higher monomer.

  The (meth) acrylic compounds include styrene, divinylbenzene, vinyl-4-t-butylbenzoate, vinyl n-butyl ether, vinyl isobutyl ether, vinyl n-butyrate, vinyl n-caprolate, and vinyl n-caprylate. Vinyl compounds such as: allyl compounds such as triallyl isocyanurate and diallyl ether phthalate.

  In addition, as said (meth) acrylic-type compound, one type of compound may be used and several types may be mixed and used.

(I-4) Photoreaction initiator When a photosensitive dry film resist to which a photoreaction initiator is added is exposed, a crosslinking reaction or a polymerization reaction can be promoted in the exposed region. As a result, the solubility of the photosensitive dry film resist in the aqueous developer can be made sufficiently different between the exposed area and the unexposed area. Therefore, the pattern is suitably formed on the photosensitive dry film resist. It becomes possible to develop.

  Examples of the photoreaction initiator include a radical generator, a photocation generator, a photobase generator, and a photoacid generator.

  The radical generator is a general term for compounds that generate radicals by light irradiation. The radical generator used in the present invention is not particularly limited as long as it is a compound that generates radicals by light irradiation, but is preferably a compound that generates radicals by light irradiation at 250 to 450 nm.

  Specific examples of such radical generator include, for example, the following general formulas (8) and (9):

(In the general formulas (8) and (9), R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ are C ₆ H _5- , C ₆ H ₄ (CH ₃ )-, C _6. H ₂ (CH ₃ ) ₃ —, (CH ₃ ) ₃ C—, C ₆ H ₃ Cl ₂ —, a methoxy group, or an ethoxy group.
The acyl phosphine oxide compound represented by these can be mentioned. The radicals generated thereby can react with a reactive group having a double bond (such as vinyl, acryloyl, methacryloyl, or allyl) to promote crosslinking.

  The acylphosphine oxide represented by the general formula (8) generates two radicals, whereas the acylphosphine oxide represented by the general formula (9) Generate radicals. Therefore, in the present invention, it is more preferable to use the acylphosphine oxide represented by the general formula (9).

  More specifically, the radical generator is preferably one that generates radicals by light having a long wavelength of about 250 to 450 nm, for example, g-line, such as 2,2-dimethoxy-1,2-diphenylethane. Ketone compounds such as -1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxy) Phosphine oxide compounds such as benzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) Mention may be made of titanocene compounds such as 1-yl) -phenyl) titanium. In particular, it is preferable to use a phosphine oxide compound or a titanocene compound.

  Examples of the photocation generator include diphenyliodonium salts such as diphenyliodonium salt of dimethoxyanthraquinone sulfonic acid, triphenylsulfonium salts, pyririnium salts, triphenylonium salts, diazonium salts, and the like. In addition to the above salts, it is preferable to mix an alicyclic epoxy or vinyl ether compound having high cation curability.

  Further, as the photobase generator, benzyl alcohol-urethane compound obtained by reaction of nitrobenzyl alcohol or dinitrobenzyl alcohol and isocyanate, nitro-1-phenylethyl alcohol, dinitro-1-phenylethyl alcohol and isocyanate can be used. Examples thereof include a phenyl alcohol-urethane compound obtained by the reaction, a propanol-urethane compound obtained by the reaction of dimethoxy-2-phenyl-2-propanol and isocyanate.

  Examples of the photoacid generator include compounds that generate sulfonic acids such as iodonium salts, sulfonium salts, and onium salts, and compounds that generate carboxylic acids such as naphthoquinone diazide. Alternatively, since compounds such as diazonium salts and bis (trichloromethyl) triazines can generate sulfone groups by light irradiation, these compounds can also be preferably used.

  In the photosensitive dry film resist according to the present invention, a peroxide and a sensitizer may be used in combination as the photoreaction initiator. By setting it as this structure, the photosensitive dry film resist can achieve the photosensitivity which can be provided to practical use.

  The peroxide is not particularly limited, and various peroxides can be used. Specifically, examples of the peroxide include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, peroxydicarbonates, and the like. In particular, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone is preferably used.

  The sensitizer is not particularly limited. For example, mihiraketone, 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, riboflavin tetrabutyrate, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2,4-dimethylthioxanthone 2,4-diethylthioxanthone, 2,4-diisopropylthio Xanthone, 3,5-dimethylthioxanthone, 3,5-diisopropylthioxanthone, 1-phenyl-2- (ethoxycarbonyl) oxyiminopropan-1-one, benzoin ether, benzoin isopropyl ether, benzanthrone, 5-nitroacenaphthene, 2-nitrofluorene, anthrone, 1,2-benzanthraquinone, 1-phenyl-5-mercapto-1H-tetrazole, thioxanthen-9-one, 10-thioxanthenone, 3-acetylindole, 2,6-di (p- Dimethylaminobenzal) -4-carboxycyclohexanone, 2,6-di (p-dimethylaminobenzal) -4-hydroxycyclohexanone, 2,6-di (p-diethylaminobenzal) -4-carboxycyclohexanone, 2, 6 Di (p-diethylaminobenzal) -4-hydroxycyclohexanone, 4,6-dimethyl-7-ethylaminocoumarin, 7-diethylamino-4-methylcoumarin, 7-diethylamino-3- (1-methylbenzimidazolyl) coumarin, 3 -(2-Benzimidazolyl) -7-diethylaminocoumarin, 3- (2-benzothiazolyl) -7-diethylaminocoumarin, 2- (p-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) quinoline, 4- (P-Dimethylaminostyryl) quinoline, 2- (p-dimethylaminostyryl) zenzothiazole, 2- (p-dimethylaminostyryl) -3,3-dimethyl-3H-indole and the like can be suitably used.

  The sensitizer may be blended within a range where a sensitizing effect is obtained and the developability is not adversely affected. Specifically, it is preferable to blend 0.01 to 50 parts by weight, and 0.1 to 20 parts by weight with respect to 100 parts by weight of the (A1) binder polymer and (A2) binder polymer. More preferred. In addition, as a sensitizer, one type of compound may be used and two or more types of compounds may be mixed and used. The peroxide is preferably blended in an amount of 1 to 200 parts by weight, more preferably 1 to 150 parts by weight, based on 100 parts by weight of the sensitizer.

  Moreover, as a combination of a photoinitiator and a sensitizer, a peroxide such as bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and 3,3 ′, 4,4′-tetra (t A combination with -butylperoxycarbonyl) benzophenone is preferred.

  The said photoinitiator can be used 1 type or in combination of 2 or more types.

  In the photosensitive dry film resist according to the present invention, the photoinitiator contains 0.01 to 50 parts by weight with respect to 100 parts by weight of the (A1) binder polymer and the (A2) binder polymer, respectively. Is preferred.

  The amount of the photoinitiator used is 0.001 to 10 weights with respect to 100 parts by weight of the total weight of the binder polymer as the component (A) and the (meth) acrylic compound as the component (B). It is preferably in the range of parts, more preferably in the range of 0.01 to 10 parts by weight. If the amount of the photoreaction initiator and / or sensitizer used is less than 0.001 part by weight, sufficient sensitivity cannot be obtained, and if it exceeds 10 parts by weight, absorption on the photosensitive dry film resist surface is achieved. May increase and the internal photocuring may be insufficient.

  As described above, the second photosensitive layer may be configured so as not to substantially contain (C2) a photoinitiator, and the blending ratio of (C2) photoinitiator is the above (A2) binder polymer. It may be 0 to 0.01 parts by weight with respect to 100 parts by weight. Moreover, 0-0.001 weight part may be sufficient with respect to 100 weight part of total weight of the binder polymer which is the said (A) component, and the (meth) acrylic-type compound which is (B) component.

  In addition, the (C1) photoinitiator of the first photosensitive layer and the (C2) photoinitiator of the second photosensitive layer may be the same or different.

  The photoreaction initiator may further contain a photopolymerization aid in order to achieve practical photosensitivity. Such a photopolymerization assistant is not particularly limited, and examples thereof include 4-diethylaminoethyl benzoate, 4-dimethylaminoethyl benzoate, 4-diethylaminopropyl benzoate, 4-dimethylaminopropyl benzoate, 4-dimethylaminoisoamyl. Benzoate, N-phenylglycine, N-methyl-N-phenylglycine, N- (4-cyanophenyl) glycine, 4-dimethylaminobenzonitrile, ethylene glycol dithioglycolate, ethylene glycol di (3-mercaptopropionate ), Trimethylolpropane thioglycolate, trimethylolpropane tri (3-mercaptopropionate), pentaerythritol tetrathioglycolate, pentaerythritol tetra (3-mercaptopro) ONATE), trimethylolethane trithioglycolate, trimethylolpropane trithioglycolate, trimethylolethanetri (3-mercaptopropionate), dipentaerythritol hexa (3-mercaptopropionate), thioglycolic acid, α Monomercaptopropionic acid, t-butylperoxybenzoate, t-butylperoxymethoxybenzoate, t-butylperoxynitrobenzoate, t-butylperoxyethylbenzoate, phenylisopropylperoxybenzoate, di-t-butyldiperoxyisophthalate, tri-t -Butyl triperoxy trimellitate, tri t-butyl triperoxy trimellitate, tetra t-butyl tetraperoxypyromellitate, 2,5-dimethyl-2,5-di Benzoylperoxy) hexane, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-hexylperoxycarbonyl) benzophenone, 2,6-di (p-azidobenzal) -4-hydroxycyclohexanone, 2,6-di (p-azidobenzal) -4-carboxycyclohexanone, 2,6 -Di (p-azidobenzal) -4-methoxycyclohexanone, 2,6-di (p-azidobenzal) -4-hydroxymethylcyclohexanone, 3,5-di (p-azidobenzal) -1-methyl-4-piperidone, 3, , 5-Di (p-azidobenzal) -4-piperidone, 3,5-di (p-aziben) ) -N-acetyl-4-piperidone, 3,5-di (p-azidobenzal) -N-methoxycarbonyl-4-piperidone, 2,6-di (p-azidobenzal) -4-hydroxycyclohexanone, 2,6 -Di (m-azidobenzal) -4-carboxycyclohexanone, 2,6-di (m-azidobenzal) -4-methoxycyclohexanone, 2,6-di (m-azidobenzal) -4-hydroxymethylcyclohexanone, 3,5- Di (m-azidobenzal) -N-methyl-4-piperidone, 3,5-di (m-azidobenzal) -4-piperidone, 3,5-di (m-azidobenzal) -N-acetyl-4-piperidone, 3,5-di (m-azidobenzal) -N-methoxycarbonyl-4-piperidone, 2,6-di (p-azidocinnamylidene -4-hydroxycyclohexanone, 2,6-di (p-azidocinnamylidene) -4-carboxycyclohexanone, 2,6-di (p-azidocinnamylidene) -4-cyclohexanone, 3,5-di (p -Azidocinamylidene) -N-methyl-4-piperidone, 4,4'-diazidochalcone, 3,3'-diazidochalcone, 3,4'-diazidochalcone, 4,3'-diazidochalcone 1,3-diphenyl-1,2,3-propanetrione-2- (o-acetyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (on-propylcarbonyl) Oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (o-methoxycarbonyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (O-ethoxycarbonyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (o-benzoyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- ( o-phenyloxycarbonyl) oxime, 1,3-bis (p-methylphenyl) -1,2,3-propanetrione-2- (o-benzoyl) oxime, 1,3-bis (p-methoxyphenyl)- 1,2,3-propanetrione-2- (o-ethoxycarbonyl) oxime, 1- (p-methoxyphenyl) -3- (p-nitrophenyl) -1,2,3-propanetrione-2- (o -Phenyloxycarbonyl) oxime can be used. Further, as another photopolymerization assistant, trialkylamines such as triethylamine, tributylamine, and triethanolamine can be mixed.

  In addition, as a photopolymerization adjuvant, one type of compound may be used and it may be used in combination of 2 or more types of compounds.

  The photopolymerization assistant may be blended within a range where a sensitizing effect is obtained and the developability is not adversely affected. Specifically, it is preferable that 0.01 to 50 parts by weight is blended with respect to 100 parts by weight of the (A1) binder polymer and the (A2) binder polymer, respectively, and the range of 0.1 to 20 parts by weight is included. Further preferred.

(I-5) Flame retardant In this specification, "flame retardant" is a substance that acts to make a flammable substance difficult to burn by adding or reacting with a flammable substance such as plastic, wood, or fiber. Means that.

In the present invention, a metal hydrate is used as the flame retardant. Metal hydrate is expressed as M _x (OH) _y or M _x O _y (H ₂ O) _z (where M is a metal x, y, and z are arbitrary integers) and releases water when heated. It exhibits flame retardancy.

  In the present invention, the metal hydrate is not particularly limited, but an alkaline earth metal or aluminum metal hydrate is preferable. In particular, aluminum hydroxide or magnesium hydroxide which is a metal hydrate of aluminum or magnesium is particularly preferable.

  Since it mixes with photosensitive resin, the one where the particle size of metal hydrate is small is preferable. The particle size of the metal hydrate is preferably 50 μm or less, more preferably 10 μm or less, and even more preferably 1 μm or less. In particular, if it is 1 μm or less, light scattering can be suppressed and the photosensitivity tends to be improved.

  However, when a large amount of flame retardant is added, the electrical reliability tends to decrease.

  Therefore, in the photosensitive dry film resist having a multilayer structure of the present invention, the flame retardant content of the second photosensitive layer is 0 to 10% by weight, and the flame retardant content of the first photosensitive layer is 100. In this case, the flame retardant content of the second photosensitive layer should satisfy the condition that it is 0 or more and 50 or less. By increasing the flame retardant content of the first photosensitive layer, imparting flame retardancy, lowering the flame retardant content of the second photosensitive layer, or by not containing any flame retardant, moisture resistance, Electrical reliability can be further increased. Furthermore, since the second photosensitive layer in contact with the substrate is excellent in alkali solubility, it is difficult for residues to be generated during alkali development, and the developability and resolution can be further improved. In addition, if the alkali solubility of the 2nd photosensitive layer which contact | connects a base material is excellent, even if the alkali solubility of a 1st photosensitive layer is inferior, it will become difficult to generate | occur | produce a residue.

  The flame retardant content of the second photosensitive layer may be from 0 to 10% by weight, but it is preferably less, preferably from 0 to 5% by weight, and from 0 to 1% by weight. Is more preferable. If the flame retardant content of the second photosensitive layer exceeds 10% by weight, the electrical reliability and alkali developability may deteriorate.

  Further, in the photosensitive dry film resist having a multilayer structure according to the present invention, when the flame retardant content of the first photosensitive layer is 100, the flame retardant content of the second photosensitive layer is preferably 0 or more and 50 or less. 0 or more and 20 or less is more preferable, and 0 or more and 10 or less is more preferable. When the flame retardant content of the first photosensitive layer is 100, and the flame retardant content of the second photosensitive layer exceeds 50, if the flame retardant content of the second photosensitive layer is in the above range, the photosensitivity Since the amount of the flame retardant contained in the entire dry film resist is small and sufficient flame retardancy may not be imparted, it is not preferable.

  The flame retardant content of the first photosensitive layer is preferably from 1 to 50% by weight, more preferably from 5 to 40% by weight, further preferably from 10 to 40% by weight, most preferably from 10 to 30% by weight. preferable. When the flame retardant content of the first photosensitive layer is less than 1% by weight, a sufficient flame retardant effect may not be obtained. On the other hand, if it exceeds 50% by weight, the physical properties of the cured product may be adversely affected.

  In the present invention, when (D2) flame retardant is contained in the second photosensitive layer, (D1) flame retardant of the first photosensitive layer and (D2) flame retardant of the second photosensitive layer are the same. It may or may not be.

(I-6) Other components The photosensitive resin composition of the present invention includes the above (A) binder polymer, (B) (meth) acrylic compound, (C) photoreaction initiator and (D) flame retardant. In addition, other components (E) may be contained as required. Examples of other components include an epoxy resin, a curing accelerator and / or a curing agent, a polymerization inhibitor, an adhesion imparting agent, a filler, a storage stabilizer, and an ion scavenger.

  That is, the first photosensitive layer of the photosensitive dry film resist according to the present invention contains (A1) a binder polymer, (B1) (meth) acrylic compound, (C1) a photoreaction initiator, and (D1) a flame retardant. However, (E1) Other components may be included.

  Moreover, if the 2nd photosensitive layer of the photosensitive dry film resist concerning this invention contains (A2) binder polymer, (B2) (meth) acrylic-type compound, and preferably (C2) photoreaction initiator. (E2) Other components may be included.

<Epoxy resin>
By using an epoxy resin, the adhesiveness with respect to copper foil, a polyimide film, etc. can be improved to the photosensitive dry film resist manufactured.

  Although it does not specifically limit as said epoxy resin, For example, bisphenol A type epoxy, such as product name Epicoat 828,834,1001,1002,1003,1004,1005,1007,1010,1100L (Japan Epoxy Resin Co., Ltd. product), etc. Resins, product names ESCN-220L, 220F, 220H, 220HH, 180H65 (Japan Epoxy Resin Co., Ltd.) and other o-cresol novolak type epoxy resins, product names EPPN-502H (Nippon Kayaku Co., Ltd.), etc. Trishydroxyphenylmethane type epoxy resin, naphthalene aralkyl novolak type epoxy resin such as product name ESN-375, novolak type epoxy resin such as product name ESN-185 (Nippon Steel Chemical Co., Ltd.), biphenol type such as product name YX4000H Epoxy resin I can make it.

  In addition to the above, bisphenol A glycidyl ether type epoxy resin, bisphenol F glycidyl ether type epoxy resin, novolac glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, cyclic aliphatic epoxy resin, aromatic type An epoxy resin, a halogenated epoxy resin, or the like may be used.

  The epoxy resin may be used alone or in combination of two or more. In addition, it is preferable to use the said epoxy resin within the range of 1-100 weight part as needed with respect to 100 weight part of binder polymers which are (A) components, and use within the range of 0-50 weight part as needed. Is more preferable, and it is particularly preferable to use within the range of 1 to 30 parts by weight. If the epoxy resin exceeds 30 parts by weight with respect to 100 parts by weight of the (A) binder polymer, the flex resistance may be lowered.

<Curing accelerator and / or curing agent>
When an epoxy resin is used as the material of the photosensitive resin composition, a curing accelerator and / or a curing agent is added to the photosensitive resin composition in order to efficiently cure the photosensitive dry film resist produced. Also good. Although it does not specifically limit as such a hardening accelerator and / or a hardening | curing agent, For example, in order to cure | harden an epoxy resin efficiently, an imidazole type compound, an acid anhydride, a tertiary amine, hydrazines And aromatic amines, phenols, triphenylphosphines, and organic peroxides. What is necessary is just to use 1 type or in combination of 2 or more types among these hardening accelerators and / or hardening agents.

  The amount of the curing accelerator and / or curing agent used is preferably in the range of 0.1 to 20 parts by weight, based on 100 parts by weight of the binder polymer (A), and 0.5 to 20 parts by weight. It is more preferable that it is within the range of 0.5 to 15 parts by weight. When the curing accelerator and / or curing agent is less than 0.1 parts by weight with respect to 100 parts by weight of the (A) binder polymer, the epoxy resin is not sufficiently cured. May cause sex decline.

<Polymerization inhibitor, stabilizer, antioxidant>
The photosensitive resin composition of the present invention includes a photopolymerizable / thermopolymerizable functional group such as a vinyl group, an acrylic group, or a methacrylic group contained in (A) a binder polymer and / or (B) (meth) acrylic compound. At least one polymer additive selected from the group consisting of a polymerization inhibitor, a stabilizer and an antioxidant in order to prevent the group from undergoing a crosslinking reaction during storage of the photosensitive resin composition and the photosensitive dry film resist Is preferably added.

  The polymerization inhibitor is not particularly limited as long as it is generally used as a polymerization inhibitor or a polymerization inhibitor. The stabilizer is not particularly limited as long as it is generally known as a heat stabilizer or a light stabilizer. The antioxidant is not particularly limited as long as it is generally used as an antioxidant or a radical scavenger.

  The above polymerization inhibitor, stabilizer and antioxidant are not necessarily separate compounds, and one compound may be used as a polymerization inhibitor or an antioxidant.

  As a polymer additive selected from the group consisting of a polymerization inhibitor, a stabilizer and an antioxidant in the present invention, a polymerization inhibitor, a polymerization inhibitor, a heat stabilizer, a light stabilizer, an antioxidant, and a radical scavenger are generally used. Although it will not specifically limit if it is used as an agent, For example, hydroquinone, methyl hydroquinone, 2,5-di-t-butyl hydroquinone, t-butyl hydroquinone, 2,5-bis (1,1,3, 3-tetramethylbutyl) hydroquinone (trade name DOHQ, manufactured by Wako Pure Chemical Industries, Ltd.), 2,5-bis (1,1-dimethylbutyl) hydroquinone (trade name DHHQ, manufactured by Wako Pure Chemical Industries, Ltd.), etc. Hydroquinone compounds; benzoyl such as p-benzoquinone, methyl-p-benzoquinone, t-butylbenzoquinone, 2,5-diphenyl-p-benzoquinone Compound: pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: Irganox 1010, manufactured by Ciba Specialty Chemicals), N, N ′ -Hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide] (manufactured by the company, trade name: Irganox 1098), 1,3,5-tris ( 3,5-di-t-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (product name: Irganox 3114), hydroxy Hindered phenol compounds such as phenol benzotriazole (trade name Adeka AO-20 manufactured by Asahi Denka Kogyo Co., Ltd.); 2- (2H-benzotriazole- -Il) -p-; Benzotriazole compounds such as Cresol (Ciba Specialty Chemicals, trade name TINUVIN P); N-nitrosophenylhydroxylamine (Wako Pure Chemical Industries, trade name) Nitrosamine compounds such as Q-1300) and N-nitrosophenylhydroxylamine aluminum salt (trade name Q-1301 manufactured by Wako Pure Chemical Industries, Ltd.); organic sulfur compounds such as phenothiazine, dithiobenzoyl sulfide and dibenzyltetrasulfide; Bis (1,2,2,6,6-pentamethyl-4-piperidyl) [{3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl} methyl] butyl malonate (Ciba Special Hindered amine compounds such as Tea Chemicals Co., Ltd., trade name Irganox 144) Aromatic aromatic amines such as p-phenylenediamine (commonly called paramine) and N, N-diphenyl-p-phenylenediamine; tris (2,4-di-t-butylphenyl) phosphite (trade name, Irganox 168, manufactured by the same company); Phosphorus compounds such as tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonate (product name: Irganox P-EPQ) Can be mentioned.

  Particularly preferred are hydroquinone compounds, hindered phenol compounds, nitrosamine compounds, and aromatic amines. By using these compounds, the crosslinking reaction of the photopolymerizable / thermopolymerizable functional group can be prevented, so that the viscosity of the organic solvent solution of the photosensitive resin composition increases during storage of the photosensitive resin composition. In addition to improving the storage stability of the photosensitive dry film resist, it also has an antioxidant effect, so that it can prevent deterioration of the resin, and the photosensitivity after curing produced from the photosensitive resin composition The long-term heat resistance and hydrolysis resistance of the dry film resist can be improved.

  The amount of the polymerization inhibitor used is in the range of 0.00001 to 5 parts by weight with respect to 100 parts by weight of the total weight of the binder polymer as the component (A) and the (meth) acrylic compound as the component (B). It is preferably within the range, and more preferably within the range of 0.0001 to 1 part by weight. When the amount of the photoinitiator and / or sensitizer used is less than 0.00001 part by weight, the stability during storage may be reduced. When the amount exceeds 5 parts by weight, the sensitivity to active energy rays is increased. Tends to decrease.

<Adhesion imparting agent>
In order to improve the adhesion to a substrate such as a polyimide film or metal, a known so-called adhesion imparting agent may be added. In this invention, it is preferable to add to the 2nd photosensitive layer used as an adhesive surface with a base material.

  Such an adhesion-imparting agent is not particularly limited, and examples thereof include benzimidazole, benzoxazole, benzthiazole, triazole, and a silane coupling agent.

(II) Method for Producing Photosensitive Dry Film Resist Next, a method for producing a photosensitive dry film resist will be described by taking a photosensitive dry film resist having a two-layer structure as an example. Needless to say, the dry film resist is not limited to those obtained by the manufacturing method described below.

  The two-layer photosensitive dry film resist of the present invention is obtained by forming a first photosensitive layer on a support film and then forming a second photosensitive layer on the surface of the first photosensitive layer. In the case of producing a photosensitive dry film resist having two or more layers, for example, after forming the first photosensitive layer on the support film, one or more layers are formed on the surface of the first photosensitive layer. A second photosensitive layer may be formed on the surface of the formed layer.

  Hereinafter, (II-1) Preparation of photosensitive resin composition and (II-2) Production of photosensitive dry film resist will be described in this order.

(II-1) Preparation of photosensitive resin composition First, a first photosensitive layer resin composition for forming a first photosensitive layer and a second photosensitive layer resin composition for forming a second photosensitive layer are prepared.

  The first photosensitive layer resin composition comprises (A1) binder polymer, (B1) (meth) acrylic compound, (C1) photoreaction initiator, (D1) flame retardant, and (E1) other as required. The components are mixed at a certain ratio, and a solution obtained by uniformly dissolving the first photosensitive layer resin composition in an organic solvent is used as an organic solvent solution of the first photosensitive layer resin composition (hereinafter referred to as the first in this specification). It may be referred to as an organic solvent solution of one photosensitive layer).

  The second photosensitive layer resin composition is a mixture of (A2) a binder polymer, (B2) (meth) acrylic compound, and preferably (C2) a photoreaction initiator, (E2) and other components in a certain ratio. A solution obtained by uniformly dissolving the second photosensitive layer resin composition in an organic solvent is an organic solvent solution of the second photosensitive layer resin composition (hereinafter referred to as an organic solvent solution of the second photosensitive layer in the present specification). Sometimes called).

  The organic solvent is not particularly limited as long as it is an organic solvent that can dissolve the components contained in the first photosensitive layer resin composition and the second photosensitive layer resin composition. Examples of the organic solvent include ether solvents such as dioxolane, dioxane, and tetrahydrofuran, ketone solvents such as acetone and methyl ethyl ketone, and alcohol solvents such as methyl alcohol and ethyl alcohol. These organic solvents may be used alone or in combination of two or more. In addition, since the organic solvent is removed in a later step, the components contained in the first photosensitive layer resin composition and the second photosensitive layer resin composition are dissolved, and the one having the lowest boiling point is selected. This is advantageous in the manufacturing process.

(II-2) Production of photosensitive dry film resist Subsequently, the organic solvent solution of the first photosensitive layer resin composition is uniformly applied onto the support film, and then heated and / or sprayed with hot air. Thereby, the said organic solvent is removed and the 1st photosensitive layer in which the 1st photosensitive layer resin composition became a film form can be obtained. The first photosensitive layer thus formed is obtained by maintaining the photosensitive resin composition in a semi-cured state (B stage). Therefore, when performing thermocompression bonding such as heat laminating, it has appropriate fluidity and can be suitably embedded in the pattern circuit of the printed wiring board. Moreover, after embedding a pattern circuit, it can be hardened completely by performing an exposure process, a thermocompression bonding process, and a heating cure.

  The temperature at which the organic solvent solution of the first photosensitive layer resin composition is dried by performing the above heating and / or hot air blowing is the (meth) acryl group, epoxy group contained in the first photosensitive layer resin composition. What is necessary is just the temperature of the grade which curable groups, such as, do not react. Specifically, it is preferably 150 ° C. or lower, and particularly preferably 120 ° C. or lower. The drying time is preferably shorter as long as the organic solvent can be removed.

  The material for the support film is not particularly limited, but various commercially available films such as a polyethylene terephthalate (PET) film, a polyphenylene sulfide film, and a polyimide film can be used. Of the above support films, a PET film is often used because it has a certain degree of heat resistance and is relatively inexpensive. In addition, about the joint surface with the photosensitive dry film resist of a support body film, you may use what is surface-treated in order to improve adhesiveness and peelability.

  In the case of a two-layer structure, for example, the multilayer dry photosensitive dry film resist of the present invention can be obtained by forming a second photosensitive layer on the surface of the first photosensitive layer. At this time, the thickness of the second photosensitive layer is preferably 10 to 500, more preferably 20 to 400, and further preferably 50 to 300, where the thickness of the first photosensitive layer is 100. preferable. When the thickness of the first photosensitive layer is 100, if the thickness of the second photosensitive layer is larger than 500, the flame retardancy of the photosensitive dry film resist is lowered, which is not preferable. Further, when the thickness of the first photosensitive layer is 100, if the thickness of the second photosensitive layer is smaller than 10, the electrical reliability tends to decrease.

  There are two methods for forming the second photosensitive layer on the surface of the first photosensitive layer: 1) direct coating method and 2) transfer method. 1) The direct coating method is a method in which an organic solvent solution of the second photosensitive layer resin composition is applied to the surface of the first photosensitive layer and dried to form the second photosensitive layer. 2) The transfer method is the second photosensitive layer. After the organic solvent solution of the layer resin composition is applied to the surface and the solution-coated surface of the dried protective film is bonded to the first photosensitive layer, the protective film is peeled off to remove the second photosensitive layer on the surface of the first photosensitive layer. It is a method of transferring.

  In the case of the above method 1), after the first photosensitive layer is formed on the support film, the organic solvent solution of the second photosensitive layer resin composition is uniformly applied to the surface of the first photosensitive layer using a coating tool such as a gravure mesh. Then, the solvent is removed by heating and / or spraying with hot air and dried. In this way, a dry film resist having a structure of “support film / first photosensitive layer / second photosensitive layer” in which the second photosensitive layer is formed on the first photosensitive layer is obtained. Thereafter, a protective film may be further laminated on the second photosensitive layer. The protective film will be described later.

  Next, in the case of the above method 2), the organic solvent solution of the second photosensitive layer resin composition is uniformly applied to a protective film such as a PE film using an application tool such as a gravure mesh, and then heated and / or hot air is applied. Remove the solvent by spraying and dry. The thus obtained protective film with a second photosensitive layer ("protective film / second photosensitive layer") was prepared by using a first photosensitive layer with a support film (so that the second photosensitive layer surface was a bonding surface with the first photosensitive layer). “First photosensitive layer / support film”). In addition, this bonding can be performed by roll laminating at a temperature of 20 ° C to 70 ° C. Thereafter, if the protective film is peeled off, it can be used as a photosensitive dry film resist having a structure of “support film / first photosensitive layer / second photosensitive layer”.

  It is preferable to further laminate a protective film on the manufactured photosensitive dry film resist. Thereby, it is possible to prevent dust and dust in the air from adhering and to prevent deterioration in quality due to drying of the photosensitive dry film resist.

  The protective film is preferably laminated by laminating at a temperature of 10 ° C. to 50 ° C. on the surface of the second photosensitive layer of the photosensitive dry film resist. In addition, when the temperature at the time of lamination processing becomes higher than 50 degreeC, the thermal expansion of a protective film will be caused and a wrinkle and a curl may arise in the protective film after a lamination process. In addition, since the said protective film peels at the time of use, it is preferable that the joint surface of a protective film and a photosensitive dry film resist has moderate adhesiveness at the time of storage, and is excellent in peelability.

  Although it does not specifically limit as a material of the said protective film, For example, a polyethylene film (PE film), a polyethylene vinyl alcohol film (EVA film), "the copolymer film of polyethylene and ethylene vinyl alcohol" (following ( "PE + EVA) copolymer film", "PE film and (PE + EVA) copolymer film laminate", or "(PE + EVA) copolymer and polyethylene film by simultaneous extrusion" (one side is PE film) And the other surface is a (PE + EVA) copolymer film surface).

  The PE film has the advantages of being inexpensive and having excellent surface slipperiness. Further, the (PE + EVA) copolymer film has appropriate adhesion to the photosensitive dry film resist and releasability. By using such a protective film, when a sheet having three layers of a protective film, a photosensitive dry film resist, and a support film is wound up in a roll shape, the slipperiness of the surface can be improved.

(III) Printed Wiring Board The multilayer dry photosensitive dry film resist according to the present invention can be formed as an insulating protective layer on a printed wiring board. Therefore, the present invention also includes a printed wiring board formed by forming the photosensitive dry film resist according to the present invention as an insulating protective layer.

  In such a printed wiring board, the photosensitive dry film resist may be laminated so that the second photosensitive layer is in contact with a copper-clad laminate on which a circuit is formed. Therefore, when the photosensitive dry film resist has a two-layer structure including a first photosensitive layer and a second photosensitive layer, the printed wiring board is formed on the copper-clad laminate on which the circuit is formed. Are in contact with each other and the outer side is the first photosensitive layer.

  According to said structure, the printed wiring board excellent in the flame retardance, moisture resistance, and electrical reliability can be provided.

  About the method of manufacturing the printed wiring board formed by forming the multilayer dry photosensitive dry film resist as the insulating protective layer according to the present invention, the printed wiring formed by forming the double-layered photosensitive dry film resist as the insulating protective layer A case of manufacturing a plate will be described as an example. A case where a CCL formed with a pattern circuit (hereinafter also referred to as a CCL with a circuit) is used as a printed wiring board will be described as an example, but the same technique is used when forming a multilayer printed wiring board. Thus, an interlayer insulating layer can be formed.

  First, a protective film is peeled from the sheet | seat which has the protective film demonstrated above, a photosensitive dry film resist, and a support body film. Below, what peeled the protective film is described as the photosensitive dry film resist with a support film. Then, the CCL with a circuit is covered with the photosensitive dry film resist with a support film so that the second photosensitive layer side of the photosensitive dry film resist faces the circuit part of the CCL with circuit, and is bonded by thermocompression bonding. Match. The bonding by thermocompression bonding may be performed by hot pressing, laminating (thermal laminating), hot roll laminating or the like, and is not particularly limited.

  When the bonding is performed by heat laminating or heat roll laminating (hereinafter referred to as laminating), the processing temperature may be equal to or higher than the lower limit temperature (hereinafter, pressure bonding possible) at which laminating is possible. . Specifically, the temperature at which the pressure bonding is possible is preferably within a range of 50 to 150 ° C., more preferably within a range of 60 to 120 ° C., and particularly preferably within a range of 80 to 120 ° C. preferable.

  When the said process temperature exceeds 150 degreeC, the crosslinking reaction of the photosensitive reactive group contained in the photosensitive dry film resist may arise at the time of a lamination process, and hardening of the photosensitive dry film resist may advance. On the other hand, when the processing temperature is lower than 50 ° C., the fluidity of the photosensitive dry film resist is low, and it becomes difficult to embed the pattern circuit. Furthermore, adhesiveness with the copper circuit of CCL with a copper circuit and the base film of CCL with a copper circuit may fall.

  By the above-described thermocompression treatment, a sample in which a photosensitive dry film resist is laminated on a CCL with a circuit and a support film is further laminated is obtained. Next, pattern exposure and development are performed on the bonded sample. In pattern exposure and development, a photomask pattern is placed on the support film of the bonded sample, and exposure processing is performed through the photomask. Thereafter, the support film is peeled off and development processing is performed, whereby holes (vias) corresponding to the photomask pattern are formed.

  In addition, although the said support body film is peeled off after exposure processing, even if it peels after the photosensitive dry film resist with support body film is bonded together on CCL with a circuit, ie, before performing an exposure process. Good. From the viewpoint of protecting the photosensitive dry film resist, it is preferable to peel off after the exposure process is completed.

  Here, the light source used for exposure is preferably a light source that effectively emits light of 250 to 450 nm. The reason for this is that the photoreaction initiator contained in the photosensitive dry film resist normally functions by absorbing light of 450 nm or less.

  Moreover, as a developing solution used for the development processing, a basic solution in which a basic compound is dissolved may be used. The solvent for dissolving the basic compound is not particularly limited as long as it is a solvent that can dissolve the basic compound, but water is particularly preferable from the viewpoint of environmental problems.

  Examples of the basic compound include hydroxides or carbonates of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate, and organic amines such as tetramethylammonium hydroxide. A compound etc. can be mentioned. 1 type may be used for the said basic compound and 2 or more types of compounds may be used for it.

  The concentration of the basic compound contained in the basic solution is preferably in the range of 0.1 to 10% by weight, but from the point of alkali resistance of the photosensitive dry film resist, 0.1 to 5% by weight. % Is more preferable.

  The development processing method is not particularly limited, and examples thereof include a method in which a development sample is placed in a basic solution and stirring, and a method in which a developer is sprayed onto the development sample.

  In the present invention, in particular, a developing process is performed using a spray developing machine using a 1 wt% aqueous sodium carbonate solution adjusted to a liquid temperature of 40 ° C. or a 1 wt% aqueous sodium hydroxide solution as a developing solution. can do. Here, the spray developing machine is not particularly limited as long as it is an apparatus that sprays a developer on a sample.

  Here, the development time until the pattern of the photosensitive dry film resist can be drawn may be any time as long as the pattern can be drawn. It is most preferable that development can be performed in a time of 60 seconds or less. When the development time exceeds 180 seconds, productivity tends to be inferior.

  Here, as a measure of the development time, there is a method of measuring the dissolution time of the photosensitive dry film resist in the B stage (semi-cured) state. Specifically, a sample in which a photosensitive dry film resist is bonded to a glossy surface of a copper foil is unexposed and is a 1% by weight sodium carbonate aqueous solution (liquid temperature 40 ° C.) or 1% by weight water. This is a method in which a spray development process is performed at a spray pressure of 0.85 MPa using a sodium oxide aqueous solution (liquid temperature 40 ° C.) as a developer. By this spray development process, the photosensitive dry film resist is preferably dissolved and removed in a time of 180 seconds or less. When the time until the photosensitive dry film resist is dissolved and removed exceeds 180 seconds, workability tends to be lowered.

  After the exposure / development treatment is performed as described above, the photosensitive dry film resist is completely cured by heating and curing the photosensitive dry film resist. Thereby, the hardened photosensitive dry film resist becomes an insulating protective film of the printed wiring board.

  In addition, when forming a multilayer printed wiring board, the protective layer of the printed wiring board is used as an interlayer insulating layer, and after sputtering, plating, or bonding with a copper foil is further performed on the interlayer insulating layer Then, a pattern circuit may be formed and the photosensitive dry film resist may be laminated as described above. Thereby, a multilayer printed wiring board can be manufactured.

  In the present embodiment, the case where the photosensitive dry film resist is used as an insulating protective material or an interlayer insulating material for a printed wiring board has been described. However, the photosensitive dry film resist can be used for purposes other than the above.

  In addition, it cannot be overemphasized that the following invention is also contained in this invention.

  The first photosensitive layer contains (A) a binder polymer, (B) (meth) acrylic compound, (C) a photoreaction initiator and (D) a flame retardant, and the second photosensitive layer is (A) a binder polymer, ( B) A photosensitive dry film resist having a two-layer structure containing a (meth) acrylic compound and preferably (C) a photoreaction initiator and not containing (D) a flame retardant.

  In the two-layer photosensitive dry film resist, the flame retardant contained in the first photosensitive layer is preferably a phosphorus compound. The binder polymer as the component (A) is preferably a carboxyl group-containing vinyl polymer. Moreover, it is preferable that the binder polymer which is said (A) component is a polyamic acid, and it is more preferable that it is the polyamic acid which used polysiloxane diamine represented by General formula (1) as a part of raw material.

(In the formula, each R ₁ independently represents a hydrocarbon having 1 to 5 carbon atoms, each R ₂ independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, n represents an integer of 1 to 20.)

  Moreover, it is preferable that the binder polymer which is said (A) component is the soluble polyimide which has a carboxyl group and / or a hydroxyl group which used polysiloxane diamine represented by General formula (1) as a part of raw material.

(In the formula, each R ₁ independently represents a hydrocarbon having 1 to 5 carbon atoms, each R ₂ independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, n represents an integer of 1 to 20.)
When the thickness of the first photosensitive layer is 100, the thickness of the second photosensitive layer is preferably 500 or less. Moreover, it is preferable to apply | coat and dry the organic solvent solution of a 2nd photosensitive layer on the surface of a 1st photosensitive layer, and to form a 2nd photosensitive layer. In addition, after the organic solvent solution of the second photosensitive layer is applied to the surface and the solution coating surface of the dried protective film is bonded to the first photosensitive layer, the protective film is peeled off to remove the second photosensitive layer on the surface of the first photosensitive layer. It is preferred to transfer the layer.

  Another invention of the present invention is a printed wiring board characterized in that the photosensitive dry film resist having the two-layer structure is used as an insulating protective layer.

  Furthermore, another invention of the present invention provides (A) a binder polymer, (B) a (meth) acrylic compound, (C) a photoreaction initiator, and (D) a surface of a first photosensitive layer containing a flame retardant. The organic solvent solution of the second photosensitive layer containing a binder polymer, (B) (meth) acrylic compound, and preferably (C) a photoreaction initiator, and (D) a flame retardant is applied and dried. And a photosensitive dry film resist having a two-layer structure for forming a second photosensitive layer.

  Furthermore, another invention of the present invention is the second photosensitive layer containing (A) a binder polymer, (B) a (meth) acrylic compound, and preferably (C) a photoreaction initiator, and (D) no flame retardant. The solution-coated surface of the protective film coated on the surface with the organic solvent solution of (A) contains (A) a binder polymer, (B) (meth) acrylic compound, (C) a photoreaction initiator, and (D) a flame retardant. After the lamination to the first photosensitive layer, the protective film is peeled off to transfer the second photosensitive layer onto the surface of the first photosensitive layer, thereby producing a photosensitive dry film resist having a two-layer structure.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to these. Preparation of the photosensitive resin composition, specific production of the photosensitive dry film resist, and evaluation of its physical properties were performed as follows. Moreover, the binder polymer used in the following examples and comparative examples was manufactured by the method shown in the following synthesis examples 1-4.

<Preparation of photosensitive resin composition>
The first photosensitive layer resin composition comprises (A1) binder polymer, (B1) (meth) acrylic compound, (C1) photoreaction initiator, (D1) flame retardant, and (E1) other as required. An organic solvent solution of the first photosensitive layer resin composition is prepared by mixing the components at a predetermined ratio, adding dioxolane so that the solid content weight% (Sc) = 40%, and uniformly dissolving the solution. Manufactured as. Similarly, the second photosensitive layer resin composition comprises (A2) a binder polymer, (B2) (meth) acrylic compound, and preferably (C2) a photoreaction initiator, and optionally (E2) other An organic solvent solution of the second photosensitive layer resin composition is prepared by mixing the components at a predetermined ratio, adding dioxolane so that the solid content weight% (Sc) = 30%, and uniformly dissolving the solution. Manufactured as. Here, solid content weight is materials other than an organic solvent, and shows the total weight of (A), (B), (C), (D), and (E) component. For example, in the case of the first photosensitive layer resin composition, the total weight of the components (A1), (B1), (C1), (D1) and (E1) is shown, and the weight of the liquid material other than the organic solvent is liquid. However, it shall be included in the weight as a solid content.

<Production of photosensitive dry film resist>
The organic solvent solution of the first photosensitive layer resin composition was applied to a support film so that the thickness after drying (the thickness of the photosensitive dry film resist) was 20 μm. As the support film, a PET film (Lumilar manufactured by Toray Industries, Inc., thickness 25 μm) was used. Thereafter, the organic solvent was removed by drying the coating layer on the support film at 100 ° C. for 10 minutes. This obtained the sheet | seat which consists of a 1st photosensitive layer / PET film. The first photosensitive layer is in a B stage state.

  Next, a second photosensitive layer was formed on the surface of the first photosensitive layer. The second photosensitive layer was formed by the following two methods: direct coating method and transfer method.

1) Direct coating method In the case of the direct coating method, the organic solvent solution of the second photosensitive layer resin composition is applied to the surface of the first photosensitive layer produced as described above so that the thickness after drying becomes 5 μm, and 100 ° C. For 5 minutes to remove the organic solvent.

  On the thus produced support film / photosensitive dry film resist, as a protective film, a “film produced by the simultaneous extrusion method of (EVA + PE) copolymer and polyethylene” (Protect (# 6221F) manufactured by Sekisui Chemical Co., Ltd.) ) Film (thickness 50 μm)) was laminated under the conditions of a roll temperature of 40 ° C. and a nip pressure of 50000 Pa · m so that the (EVA + PE) copolymer film surface was in contact with the photosensitive dry film resist surface.

2) Transfer method An organic solvent solution of the second photosensitive layer resin composition was applied onto a PPS film (Torelina # 3000 manufactured by Toray Industries, Inc., thickness 25 μm) so that the thickness after drying was 5 μm, and 100 ° C. And dried for 5 minutes to remove the organic solvent.

  The protective film with the second photosensitive layer produced in this way was in contact with the surface of the first photosensitive layer produced as described above, with the roll temperature of 45 ° C. and the nip pressure of 50000 Pa · m. Laminated. This PPS film is first peeled off when a photosensitive dry film resist is used.

  Note that the two-layer photosensitive dry film resist manufactured by the direct coating method or the transfer method is in a B-stage state.

<Evaluation of physical properties of photosensitive dry film resist>
About the photosensitive dry film resist manufactured as mentioned above, the physical property of each item shown next was evaluated. Specifically, (i) alkali solubility, (ii) developability, (iii) resolution, (iv) adhesion, (v) flame retardancy, (vi) electrical reliability, (vii) solder heat resistance, ( viii) Evaluation of tackiness in the B stage state, and (iv) warpage.

(I) Alkali solubility First, an electrolytic copper foil (manufactured by Mitsui Kinzoku Co., Ltd., thickness 38 μm) is soft-etched with a 10 wt% sulfuric acid aqueous solution for 1 minute (this is a step of removing a rust inhibitor on the copper foil surface) After washing with water, the surface was washed with ethanol and acetone and then dried. After peeling off the protective film of the photosensitive dry film resist, it was laminated on the glossy surface of the electrolytic copper foil (after soft etching) at 100 ° C. and 75000 Pa · m. Next, after peeling the PET film, using a spray developing machine (etching machine ES-655D manufactured by Sanhayato Co., Ltd.), a 1% by weight sodium carbonate aqueous solution (liquid temperature: 40 ° C.) with a development time of 30 to 180 seconds. Development processing was performed under the conditions. The developed sample was washed with distilled water to remove the developer and dried. The shortest development time required to completely remove the photosensitive dry film resist from the glossy surface of the copper foil to which the photosensitive dry film resist was bonded was defined as the alkali dissolution time in the B stage state. When the alkali dissolution time in a 1% by weight sodium carbonate aqueous solution (liquid temperature 40 ° C.) exceeds 180 seconds, the developer is changed to a 1% by weight sodium hydroxide aqueous solution (liquid temperature 40 ° C.). The test was carried out and the alkali dissolution time was measured.

  The developing solution of either 1 wt% aqueous sodium carbonate solution (liquid temperature 40 ° C.) or 1 wt% aqueous sodium carbonate solution (liquid temperature 40 ° C.) In the case of 60 seconds or less, it was accepted, and those exceeding 180 seconds were rejected.

(Ii) Developability First, an electrolytic copper foil (manufactured by Mitsui Kinzoku Co., Ltd., thickness 38 μm) is soft-etched with a 10% by weight sulfuric acid aqueous solution for 1 minute (this is a step of removing a rust inhibitor on the surface of the copper foil) and washed with water. Thereafter, the surface was washed with ethanol and acetone and then dried. After peeling off the protective film of the photosensitive dry film resist, it was laminated on the glossy surface of the electrolytic copper foil (after soft etching) under the conditions of 100 ° C. and 75000 Pa · m. A mask pattern on which fine squares of 100 × 100 μm square and 200 × 200 μm square were drawn was placed on the PET film of this laminate, and light having a wavelength of 405 nm was exposed by 300 mJ / cm ² . After peeling off the PET film of this sample, using a spray developing machine (etching machine ES-655D manufactured by Sanhayato Co., Ltd.), 1 wt% sodium hydroxide aqueous solution (liquid temperature 40 ° C.) or 1 wt% carbonic acid Spray development was performed using an aqueous sodium solution (liquid temperature 40 ° C.). In the above alkaline solubility test, the developer used was a sodium carbonate aqueous solution as the developer when dissolved in a sodium carbonate aqueous solution, and a sodium hydroxide aqueous solution as the developer when dissolved in only sodium hydroxide. It was. The pattern formed by development was then washed with distilled water to remove the developer and dried. When it was observed with an optical microscope and at least 200 [mu] m * 200 [mu] m squares could be developed without residue, it was judged as acceptable.

(Iii) Resolution Under the same conditions as the above developability, a photosensitive dry film resist was laminated on the glossy surface of the electrolytic copper foil. On the PET film of this laminate, a mask pattern with a line / space of 40/40 μm to 200/200 μm in increments of 10 μm was placed, and light with a wavelength of 405 nm was exposed by 300 mJ / cm ² . After peeling off the PET film of this sample, using a spray developing machine (etching machine ES-655D manufactured by Sanhayato Co., Ltd.), 1% by weight sodium hydroxide aqueous solution (liquid temperature 40 ° C.) or 1% by weight carbonic acid carbonate. Spray development processing was performed using an aqueous sodium solution (liquid temperature 40 ° C.), and the minimum line width that could remove the unexposed area cleanly was measured, and this was taken as the resolution. The smaller the numerical value, the better the resolution. In the above alkaline solubility test, the developer used was a sodium carbonate aqueous solution as the developer when dissolved in a sodium carbonate aqueous solution, and a sodium hydroxide aqueous solution as the developer when dissolved in only sodium hydroxide. It was.

(Iv) Adhesiveness After peeling off the protective film of the photosensitive dry film resist, it was laminated to a polyimide film having a thickness of 25 μm (NPI manufactured by Kaneka Corporation) at 100 ° C. and 75000 Pa · m. Next, after exposing the light of wavelength 405nm only by 600mJ / cm < ² >, the support body film was peeled and heat-cured in 180 degreeC oven for 2 hours.

  The thus-produced “polyimide film / photosensitive dry film resist” laminate sample was subjected to a cross-cut peel test in accordance with IPC TM650 2.4.28.1.

(V) Flame retardance After peeling off the protective film of the photosensitive dry film resist, it was laminated at 100 ° C. and 75000 Pa · m on both sides of a 50 μm-thick polyimide film (NPI manufactured by Kaneka Corporation). Next, light having a wavelength of 405 nm was exposed on both sides by 600 mJ / cm ² , and then the support films (PET) on both sides were peeled off, followed by heat curing in an oven at 180 ° C. for 2 hours.

  The thus produced “photosensitive dry film resist / polyimide film / photosensitive dry film resist” laminate sample was tested according to the UL94 thin material vertical combustion test (VTM-0).

(Vi) Electrical Reliability Polyimide film with copper foil (manufactured by Nippon Steel Chemical Co., Ltd., trade name Espanex, polyimide film thickness 25 μm, copper foil thickness 18 μm), copper foil surface, resist film (Asahi Kasei Corporation) 1 and FIG. 2 were used to form comb patterns with lines / spaces = 100/100 μm and 25/25 μm, respectively, to obtain CCL with circuits. The photosensitive dry film resist from which the protective film was peeled was laminated so as to cover the comb-shaped pattern portion of the CCL with circuit, and was laminated under the conditions of 100 ° C. and 75000 Pa · m. The photosensitive dry film resist surface of the bonded sample was exposed to light having a wavelength of 405 nm for 300 mJ / cm ² , and then the PET film was peeled off and cured by curing at 180 ° C. for 2 hours.

  This sample was placed in a thermo-hygrostat (trade name Platinum PR-2K, manufactured by ESPEC) with a temperature of 85 ° C./relative humidity of 85%, and a voltage of 60 V was continuously applied between the terminals of the comb pattern. The insulation resistance between lines was measured every minute.

At least when the resistance value at the time of application time is 500 hours is 1.0 × 10 ⁸ Ω or more in a comb pattern of line / space = 100/100 μm, the circuit is shorted in less than 500 hours. Those that would have been rejected. It can be said that the electrical reliability is better if the comb / pattern of line / space = 25/25 μm retains a resistance value of 1.0 × 10 ⁸ Ω or more.

(Vii) Solder heat resistance Copper foil (electrolytic copper foil manufactured by Mitsui Kinzoku Co., Ltd., thickness 38 μm) is cut into 5 cm square, soft etched with 10% by weight sulfuric acid aqueous solution for 1 minute, washed with water, and the surface is washed with ethanol and acetone. Washed and dried. Next, the protective film of the photosensitive dry film resist cut into 4 cm square was peeled off, and was laminated on the glossy surface of the electrolytic copper foil (after soft etching) and laminated under the conditions of 100 ° C. and 75000 Pa · m. The photosensitive dry film resist surface of this bonded sample was exposed to 300 mJ / cm ² of light having a wavelength of 405 nm, and then cured by curing at 180 ° C. for 2 hours. This sample was conditioned at <1> normal condition (24 hours in an environment of 20 ° C./40% relative humidity), <2> moisture absorption (48 hours in an environment of 40 ° C./85% relative humidity), and then melted at 260 ° C. or higher. The sample was floated on the solder for 30 seconds, and the maximum temperature at which no swelling or peeling occurred at the interface between the copper foil and the photosensitive dry film resist was measured. If there was solder heat resistance of at least 260 ° C. or higher, the test was accepted.

(Viii) Tack property in B stage state After peeling off the protective film of the photosensitive dry film resist, the presence or absence of tack is examined by finger touch. did.

(Iv) Warpage Polyimide film Apical 25 NPI (manufactured by Kaneka) was combined with a photosensitive dry film resist prepared in the same manner as in the measurement of adhesion, and laminated under conditions of 110 ° C. and 20000 Pa · m. Subsequently, 400 m light was exposed by 300 mJ / cm ² , and then the PET film was peeled off and heated at 180 ° C. for 2 hours to obtain a laminate. This laminate was cut into 5 cm pieces to obtain 5 cm × 5 cm test samples. After leaving the test sample in an environment of 23 ° C. and 65% RH for 24 hours, place the photosensitive dry film resist side up on a flat table, and measure the maximum height of the part that has been warped from the table with a ruler. Warpage (mm) was used. A warp of 5 mm or less was regarded as an acceptable line.

<Synthesis of binder polymer>
As raw materials, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride (hereinafter also referred to as “BTDA”), 3,3 ′, 4,4′-biphenyl ether tetra as acid dianhydride. Carboxylic dianhydride (hereinafter also referred to as “ODPA”), pyromellitic dianhydride, 3,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (hereinafter also referred to as “s-BPDA”) 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride as an aromatic diamine and 1,3-bis (3-Aminophenoxy) benzene, 2,2-bis (3-aminophenyl) propane, 3,3′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane were used. As the solvent, N-methylpyrrolidone (hereinafter also referred to as “NMP”), N, N′-dimethylformamide (hereinafter also referred to as “DMF”) and dioxolane were used.

  The weight average molecular weight of the obtained binder polymer was calculated in terms of polyethylene oxide by size exclusion chromatography using HLC8220GPC manufactured by Tosoh Corporation.

<Synthesis Example 1: Polyamic acid>
In a 2000 ml separable flask equipped with a stirrer, 29.23 g (100 mmol) of 1,3-bis (3-aminophenoxy) benzene was taken, dissolved in 58.46 g of dimethylformamide, and stirred at room temperature for 1 hour. . Next, 31.02 g (100 mmol) of 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride was added, and stirring was continued for 3 hours to obtain polyamic acid. The polyamic acid had a weight average molecular weight of 100,000.

<Synthesis Example 2: Polyamic acid>
In a 2000 ml separable flask equipped with a stirrer, 31.02 g (100 mmol) of 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride and 102.7 g of dimethylformamide were taken and polysiloxane diamine manufactured by Shin-Etsu Chemical Co., Ltd. 59.68 g (40 mmol: molecular weight 1492) of X-22-9409S was dissolved in 59.68 g of dimethylformamide, and the mixture was stirred at room temperature for 1 hour. Then, 17.54 g (60 mmol) of 1,3-bis (3-aminophenoxy) benzene was added and stirring was continued for 3 hours to obtain a polyamic acid. The weight average molecular weight of this polyamic acid was 80000.

<Synthesis Example 3: Polyamic acid>
In a 3 L separable flask, a stirrer, a reflux condenser, a dropping funnel and a nitrogen introducing tank were installed. Under a nitrogen atmosphere, 87.3 g (400 mmol) of pyromellitic dianhydride and 496 g of N-methylpyrrolidone were put into the flask. While stirring this, the internal temperature was raised to 50 ° C. At that temperature, 92.6 g of polysiloxane diamine BY16-853U manufactured by Toray Dow Corning Silicone Co., Ltd. (R2 = propylene group, m is about 10, and phenyl group content is 0%) in general formula (5) from the dropping funnel. (100 mmol: molecular weight 926) was added dropwise in small portions over 2 hours. After completion of the dropwise addition, stirring was continued for 1 hour at that temperature. Thereafter, the reaction temperature was cooled to 30 ° C. or lower, and 87.7 g (300 mmol) of 1,3-bis (3-aminophenoxy) benzene was added and stirring was continued in a nitrogen atmosphere for 20 hours to obtain polyamic acid. The polyamic acid had a weight average molecular weight of 120,000.

<Synthesis Example 4: Soluble polyimide having a carboxyl group and / or a hydroxyl group>
In a 500 ml separable flask equipped with a stirrer, 17.3 g (30 mmol) of (2,2-bis (hydroxyphenyl) propanedibenzoate) -3,3 ′, 4,4′-tetracarboxylic dianhydride, 30 g of dimethylformamide was added and dissolved by stirring with a stirrer. Next, 5.15 g (18 mmol) of [bis (4-amino-3-carboxy) phenyl] methane was dissolved in 9 g of dimethylformamide, and the above (2,2-bis (hydroxyphenyl) propanedibenzoate)- Added to the solution of 3,3 ′, 4,4′-tetracarboxylic dianhydride and stirred vigorously. When the solution became homogeneous, 7.47 g (9 mmol) of polysiloxane diamine KF-8010 manufactured by Shin-Etsu Chemical Co., Ltd. was added to the above solution and stirred vigorously. When the solution became homogeneous, finally, 1.29 g (3 mmol) of bis [4- (3-aminophenoxy) phenyl] sulfone was added and stirred vigorously for 1 hour. The polyamic acid solution thus obtained was placed on a vat coated with a fluororesin and dried under reduced pressure in a vacuum oven at 200 ° C. and a pressure of 660 Pa for 2 hours to obtain 26.40 g of a polyimide having a carboxyl group. The weight average molecular weight of this polyimide was 37000.

[Example 1]
<Production of photosensitive dry film resist>
The following components are mixed, and dioxolane is added and uniformly dissolved so that the solid content weight% (Sc) = 40%. The organic solvent solution of the first photosensitive layer and the organic solvent solution of the second photosensitive layer are mixed. Manufactured.

<Organic solvent solution of first photosensitive layer>
(A1) Binder polymer / carboxyl group-containing vinyl polymer (manufactured by Daicel Cytec Co., Ltd., product name ACA320, weight average molecular weight 25000)... 100 parts by weight (B1) (meth) acrylic compound / bisphenol A EO modified Di (meth) acrylate (manufactured by Daicel Cytec Co., Ltd., product name EB150) ... 20 parts by weight Bisphenol A EO-modified di (meth) acrylate (manufactured by Hitachi Chemical Co., Ltd., product name FA321M) ... 20 parts by weight (C1) Photoinitiator, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) ... 1 part by weight ( D1) Flame retardant, aluminum hydroxide (Hajilite H-43M, manufactured by Showa Denko KK) 60 parts by weight.

<Organic solvent solution of second photosensitive layer>
(A2) Binder polymer / carboxyl group-containing vinyl polymer (manufactured by Daicel Cytec Co., Ltd., product name ACA320 weight average molecular weight 25000)... 100 parts by weight (B2) (meth) acrylic compound pentapentol acrylate (Product name: M305, manufactured by Toa Gosei Co., Ltd.) 40 parts by weight (C2) Photoinitiator Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals Co., Ltd.) ) Irgacure 819) ... 1 part by weight An organic solvent solution of the photosensitive resin composition having the above composition was prepared, and the first photosensitive layer was 12.5 μm thick and the second photosensitive layer was 12.5 μm by the transfer method. A thick B-stage photosensitive dry film resist was produced.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Resolution: 70μm
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / space = 100/100 μm: 1.7 × 10 ⁸ Ω, line / space = 25/25 μm: 4.5 × 10 ⁶ Ω)
Solder heat resistance: Solder heat resistance passed at 260 ° C.
T-stage tackiness in the B stage state: Tack-free and passed.
Warpage: Passed at 4 mm.

[Example 2]
<Production of photosensitive dry film resist>
The following components are mixed, and dioxolane is added and uniformly dissolved so that the solid content weight% (Sc) = 40%. The organic solvent solution of the first photosensitive layer and the organic solvent solution of the second photosensitive layer are mixed. Manufactured.

<Organic solvent solution of first photosensitive layer>
(A1) Binder polymer • Polyamic acid synthesized in Synthesis Example 1 (converted in terms of solid content): 100 parts by weight (B1) (Meth) acrylic compound • Bisphenol A EO-modified di (meth) acrylate (Daicel Cytec) Product name EB150) ... 10 parts by weight Bisphenol A EO-modified di (meth) acrylate (manufactured by Hitachi Chemical Co., Ltd., product name FA321M) ... 40 parts by weight (C1 ) Photoinitiator • Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) 2 parts by weight (D1) Flame retardant • Aluminum hydroxide (Showa Denko KK Hajilite H-43M) ... 40 parts by weight.

<Organic solvent solution of second photosensitive layer>
(A2) Binder polymer • Polyamic acid synthesized in Synthesis Example 1 (converted as solid content): 100 parts by weight (B2) (meth) acrylic compound • Bisphenol A EO-modified di (meth) acrylate (Hitachi Chemical) Industrial Co., Ltd., product name FA321M) 40 parts by weight (C2) Photoinitiator Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals Co., Ltd.) (Irgacure 819): 1 part by weight An organic solvent solution of the photosensitive resin composition having the above composition was prepared, and the first photosensitive layer was 12.5 μ thick and the second photosensitive layer was 12.5 μ thick by direct coating. A photosensitive dry film resist in a B-stage state was produced.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Resolution: 70μm
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / Space = 100/100 μm: 5.4 × 10 ¹¹ Ω, Line / Space = 25/25 μm: 3.7 × 10 ⁸ Ω)
Solder heat resistance: Solder heat resistance passed at 290 ° C.
T-stage tackiness in the B stage state: Tack-free and passed.
Warpage: Tubular rejected.

Example 3
<Production of photosensitive dry film resist>
The following components are mixed, and dioxolane is added and uniformly dissolved so that the solid content weight% (Sc) = 40%. The organic solvent solution of the first photosensitive layer and the organic solvent solution of the second photosensitive layer are mixed. Manufactured.

<Organic solvent solution of first photosensitive layer>
(A1) Binder polymer • Polyamic acid synthesized in Synthesis Example 2 (converted to solid content): 100 parts by weight (B1) (Meth) acrylic compound • Bisphenol A EO-modified di (meth) acrylate (Daicel Cytec) Product name: EB150) ... 20 parts by weight Bisphenol A EO-modified di (meth) acrylate (manufactured by Hitachi Chemical Co., Ltd., product name: FA321M) ... 30 parts by weight (C1 ) Photoinitiator · Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) ··· 2 parts by weight (D1) Flame retardant · Magnesium hydroxide (Echo Mug Z-10, manufactured by Tateho Chemical Industries) ... 50 parts by weight.

<Organic solvent solution of second photosensitive layer>
(A2) Binder polymer • Polyamic acid synthesized in Synthesis Example 2 (converted to solid content): 100 parts by weight (B2) (meth) acrylic compound • Bisphenol A EO-modified di (meth) acrylate (Daicel Cytec) Product name EB150) ... 10 parts by weight Bisphenol A EO-modified di (meth) acrylate (manufactured by Hitachi Chemical Co., Ltd., product name FA321M) ... 20 parts by weight (C2 ) Photoinitiator / Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) 1 part by weight of the photosensitive resin composition having the above composition An organic solvent solution is prepared, and a direct dry coating method is used for the photosensitive dry fill in the B stage state in which the first photosensitive layer is 10 μm thick and the second photosensitive layer is 15 μm thick. Resist was prepared.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Resolution: 50μm
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / space = 100/100 μm: 5.6 × 10 ¹¹ Ω, line / space = 25/25 μm: 5.4 × 10 ⁸ Ω)
Solder heat resistance: Solder heat resistance passed at 290 ° C.
T-stage tackiness in the B stage state: Tack-free and passed.
Warpage: 1mm or less.

Example 4
<Production of photosensitive dry film resist>
The following components are mixed, and dioxolane is added and uniformly dissolved so that the solid content weight% (Sc) = 40%. The organic solvent solution of the first photosensitive layer and the organic solvent solution of the second photosensitive layer are mixed. Manufactured.

<Organic solvent solution of first photosensitive layer>
(A1) Binder polymer • Soluble polyimide having carboxyl group synthesized in Synthesis Example 4 ··· 100 parts by weight (B1) (Meth) acrylic compound • Modified bisphenol A type epoxy acrylate (manufactured by Daicel Cytec Co., Ltd.) Product name Ebecryl 3708) 50 parts by weight (C1) Photoinitiator Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals Co., Ltd., product name Irgacure 819) ) ... 2 parts by weight (D1) Flame retardant, aluminum hydroxide (Hajilite H-43M manufactured by Showa Denko KK) ... 40 parts by weight.

<Organic solvent solution of second photosensitive layer>
(A2) Binder polymer / soluble polyimide having carboxyl group synthesized in Synthesis Example 4 ... 100 parts by weight (B2) (meth) acrylic compound / modified bisphenol A type epoxy acrylate (manufactured by Daicel Cytec Co., Ltd.) , Product name Ebecryl 3708)... 50 parts by weight (C2) photoinitiator bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (manufactured by Ciba Specialty Chemicals Co., Ltd., product name Irgacure 819) ) ... 2 parts by weight (E2) As other component epoxy resin,
・ Bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., product name Epicoat 828) ... 10 parts by weight curing agent,
-4,4'-diaminodiphenylmethane (DDM) ... 1 part by weight An organic solvent solution of the photosensitive resin composition having the above composition was prepared, and the first photosensitive layer was 10 μm thick by the direct coating method. A photosensitive dry film resist in a B stage state having a photosensitive layer thickness of 15 μm was produced.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: 1% by weight sodium carbonate aqueous solution does not dissolve in 180 seconds. Dissolves in 30 seconds with aqueous sodium hydroxide.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Resolution: 90μm
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / Space = 100/100 μm: 5.7 × 10 ⁸ Ω, Line / Space = 25/25 μm: 3.4 × 10 ⁶ Ω)
Solder heat resistance: Solder heat resistance passed at 300 ° C.
T-stage tackiness in the B stage state: Tack-free and passed.
Warpage: Passed at 3 mm.

Example 5
The same as in Example 3 except that the organic solvent solution of the first photosensitive layer and the organic solvent solution of the second photosensitive layer in Example 2 were used, the thickness of the first photosensitive layer was 20 μm, and the thickness of the second photosensitive layer was 5 μm. Thus, a photosensitive dry film resist in a B stage state was produced.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Resolution: 50μm
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / space = 100/100 μm: 9.0 × 10 ¹¹ Ω, line / space = 25/25 μm: 1.5 × 10 ⁹ Ω)
Solder heat resistance: Solder heat resistance passed at 290 ° C.
T-stage tackiness in the B stage state: Tack-free and passed.
Warpage: 1mm or less.

[Comparative Example 1]
<Production of photosensitive dry film resist>
The following components are mixed, dioxolane is added and uniformly dissolved so that the solid content weight% (Sc) = 40%, and the organic solvent solution of the first photosensitive layer resin composition and the second photosensitive layer resin composition An organic solvent solution of the product was prepared.

<Organic solvent solution of first photosensitive layer resin composition>
(A1) Binder polymer / polyurethane resin (manufactured by Dainichi Seika Co., Ltd., product name FS-141 ... 100 parts by weight (D1) flame retardant / aluminum hydroxide (Hagilite H-43M, Showa Denko KK) ) ... 50 parts by weight.

<Organic solvent solution of second photosensitive layer resin composition>
(A2) Binder polymer / polyurethane resin (manufactured by Dainichi Seika Co., Ltd., product name FS-141... 100 parts by weight.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Both 1% by weight sodium carbonate aqueous solution and sodium hydroxide aqueous solution do not dissolve in 180 seconds.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes could not be developed and failed.
Resolution:-(development not possible)
Adhesiveness: Partial peeling and failure.
Flame resistance: Passed.
Warpage: 4 mm passed.
Electrical reliability: Passed. (Line / space = 100/100 μm: 5.4 × 10 ⁸ Ω, line / space = 25/25 μm: short circuit after 300 hours.)
Solder heat resistance: Swells at 260 ° C and fails.
T-stage tackiness in the B stage state: Tack-free and passed.

  Thus, in a non-photosensitive material in which (A) the binder polymer does not have an acidic functional group, (B) (meth) acrylic compound, and (C) no photoreaction initiator is added, developability There is no. Furthermore, adhesion and solder heat resistance are also inferior.

[Comparative Example 2]
<Production of photosensitive dry film resist>
The components shown below were mixed, and dioxolane was added and uniformly dissolved so that the solid content wt% (Sc) = 40%, thereby producing an organic solvent solution of the first photosensitive layer resin composition.

<Organic solvent solution of first photosensitive layer resin composition>
(A1) Binder polymer-Polyamic acid synthesized in Synthesis Example 3 (converted in terms of solid content) ... 100 parts by weight (B1) (Meth) acrylic compound-pentaerythritol acrylate (manufactured by Toagosei Co., Ltd.) Product name M-305) 25 parts by weight Bisphenol A EO-modified di (meth) acrylate (manufactured by Hitachi Chemical Co., Ltd., product name FA321M) 25 parts by weight (C1) photoreaction Initiator, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) 2 parts by weight (D1) Flame retardant, aluminum hydroxide (Showa Denko) (Hajilite H-43M) ··· 40 parts by weight An organic solvent solution of the photosensitive resin composition having the above composition was prepared, and the thickness of the first photosensitive layer was 25 µm. A photosensitive dry film resist in a B-stage state was prepared without providing the second photosensitive layer.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Dissolved in an aqueous solution of 1% by weight sodium carbonate in 60 seconds.
Developability: 100 μm × 100 μm square holes cannot be developed, but 200 μm × 200 μm square holes can be developed and passed.
Resolution: 150 μm
Adhesion: Pass.
Flame resistance: Passed.
Warpage: 4 mm passed.
Electrical reliability: Fail. (Line / space = 100/100 μm: short circuit after 200 hours, line / space = 25/25 μm: short circuit after 100 hours)
Solder heat resistance: Solder heat resistance passed at 260 ° C.
B-stage tackiness: Strong tackiness and failure.

  As described above, the photosensitive dry film resist not provided with the second photosensitive layer is inferior in developability, resolution, and electrical reliability, and has a high tackiness in the B stage state, resulting in poor handling.

[Comparative Example 3]
<Production of photosensitive dry film resist>
The following components are mixed, dioxolane is added and uniformly dissolved so that the solid content weight% (Sc) = 40%, and the organic solvent solution of the first photosensitive layer resin composition and the second photosensitive layer resin composition An organic solvent solution of the product was prepared. A B-stage photosensitive dry film resist having a first photosensitive layer thickness of 20 μm and a second photosensitive layer thickness of 5 μm was produced by a direct coating method.

<Organic solvent solution of first photosensitive layer resin composition>
(A1) Binder polymer-Polyamic acid synthesized in Synthesis Example 3 (converted in terms of solid content) ... 100 parts by weight (B1) (Meth) acrylic compound-Pentaerystrate acrylate (manufactured by Toagosei Co., Ltd.) Product name M-305) ... 40 parts by weight Bisphenol A EO-modified di (meth) acrylate (manufactured by Hitachi Chemical Co., Ltd., product name FA321M) ... 10 parts by weight (C1) photoreaction Initiator-bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) 2 parts by weight <Organic solvent solution of second photosensitive layer resin composition >
(A2) Binder polymer-Polyamic acid synthesized in Synthesis Example 3 (converted in terms of solid content) ... 100 parts by weight (B2) (meth) acrylic compound-pentaerythritol acrylate (manufactured by Toagosei Co., Ltd.) Product name M-305) 20 parts by weight (C2) photoinitiator bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) ··· 1 part by weight (D2) flame retardant · Aluminum hydroxide (Hajilite H-43M manufactured by Showa Denko KK) ··· 40 parts by weight.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Dissolved in an aqueous solution of 1% by weight sodium carbonate in 60 seconds.
Developability: A residue is generated at the opening of a 100 μm × 100 μm square hole and a 200 μm × 200 μm square hole, which is rejected.
Resolution:-(development not possible)
Adhesion: Pass.
Flame resistance: Fail.
Warpage: 5 mm passed.
Electrical reliability: Fail. (Line / space = 100/100 μm: short circuit after 100 hours, line / space = 25/25 μm: short circuit after 50 hours)
Solder heat resistance: Solder heat resistance passed at 260 ° C.
B-stage tackiness: Slightly tacky to some extent and passed.

  As described above, when the first photosensitive layer does not contain a flame retardant and the second photosensitive layer has a multilayer structure containing a flame retardant, the developability, resolution, flame retardancy, and electrical reliability are poor.

[Comparative Example 4]
A photosensitive dry film resist was produced under the same conditions as in Example 4 except that the thickness of the first photosensitive layer was 25 μm and the second photosensitive layer was not provided.

<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: 1% by weight sodium carbonate aqueous solution does not dissolve in 180 seconds. Dissolves in aqueous solution of sodium hydroxide in 60 seconds.
Developability: A residue is generated at the opening of a 100 μm × 100 μm square hole and a 200 μm × 200 μm square hole, which is rejected.
Resolution:-(development not possible)
Adhesion: Fail.
Flame resistance: Passed.
Warpage: Passed at 4 mm.
Electrical reliability: Fail. (Line / Space = 100/100 μm: Short circuit after 200 hours. Line / Space = 25/25 μm: Short circuit after 50 hours)
Solder heat resistance: Solder heat resistance passed at 290 ° C.
B stage tackiness: Slight tackiness is acceptable to some extent.

  Thus, in the photosensitive dry film resist which does not provide a 2nd photosensitive layer, it became inferior to developability, adhesiveness, and electrical reliability, and resulted in the tack property of a B stage state also falling.

[Comparative Example 5]
The component (A1) of the organic solvent solution of the first photosensitive layer resin composition in Example 2 was changed to the polyamic acid synthesized in Synthesis Example 1, and the thickness of the first photosensitive layer was 25 μm and the thickness of the second photosensitive layer was 0 μm (second A photosensitive dry film resist in a B-stage state, which was a photosensitive layer-free), was produced.
<Evaluation results of physical properties>
The physical property evaluation results of the obtained photosensitive dry film resist were as follows.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Resolution: 180μm
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Fail. (Line / space = 100/100 μm: short circuit in 350 hours, line / space = 25/25 μm: short circuit in 150 hours)
Solder heat resistance: Solder heat resistance passed at 280 ° C.
T-stage tackiness in the B stage state: Tack-free and passed.
Warpage: Tubular rejected.

  The blending conditions and thickness configuration of the examples are shown in Table 1, the blending conditions and thickness configurations of the comparative examples are shown in Table 2, and the physical property evaluation results are shown in Tables 3 to 4.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  As described above, the photosensitive dry film resist according to the present invention includes a multilayer including at least a first photosensitive layer containing a flame retardant and a second photosensitive layer containing no flame retardant or containing only a small amount. It has a structure. Therefore, compared with conventional one-layer structure, not only flame retardancy and electrical reliability, but also photosensitivity is improved, developability with aqueous developer; excellent resolution, flame retardancy, adhesion, moisture resistance It is possible to realize a photosensitive dry film resist that satisfies electrical reliability. Therefore, the photosensitive dry film resist according to the present invention can be used in the field of producing various resin molded products represented by films and laminates containing photosensitive polyimide. Furthermore, it can be widely applied to fields related to the manufacture of electronic components using such films and laminates.

It is a schematic diagram which shows the comb-shaped pattern (line / space = 100micrometer / 100micrometer) formed on a flexible copper-clad laminated board in the method of evaluating the migration resistance of an Example. It is a schematic diagram which shows the comb-shaped pattern (line / space = 25micrometer / 25micrometer) formed on a flexible copper-clad laminated board in the method of evaluating the migration resistance of an Example.

Claims (19)

The first photosensitive layer is (A1) a binder polymer,
(B1) (meth) acrylic compound,
(C1) containing a metal hydrate as an essential component as a photoreaction initiator, and (D1) a flame retardant,
The second photosensitive layer comprises (A2) a binder polymer, and (B2) a (meth) acrylic compound,
As an essential component,
(D2) substantially containing no flame retardant,
(D2) Regarding the flame retardant, the ratio of the weight of the flame retardant (D1) to the total weight of the first photosensitive layer is the flame retardant content of the first photosensitive layer, and the weight of the flame retardant (D2) relative to the total weight of the second photosensitive layer. Is the flame retardant content of the second photosensitive layer, the flame retardant content of the second photosensitive layer is from 0 to 10% by weight, and the flame retardant content of the first photosensitive layer is When 100, the flame retardant content of the second photosensitive layer satisfies the condition that it is 0 or more and 50 or less,
A photosensitive dry film resist having a multilayer structure including at least a first photosensitive layer and a second photosensitive layer.   The multilayer photosensitive dry film resist according to claim 1, wherein the second photosensitive layer further contains (C2) a photoreaction initiator as an essential component.   3. The photosensitive dry film resist having a multilayer structure according to claim 1, wherein the second photosensitive layer is located in an outermost layer of the multilayer structure.   4. The multilayer dry photosensitive dry film resist according to claim 1, wherein the metal hydrate (D1) is an aluminum hydroxide compound.   4. The multilayer dry photosensitive dry film resist according to claim 1, wherein the metal hydrate (D1) is a magnesium hydroxide compound.   6. The multilayer dry photosensitive dry film resist according to claim 1, wherein the (A1) binder polymer and / or (A2) binder polymer is a carboxyl group-containing vinyl polymer.   6. The multilayer dry photosensitive dry film resist according to claim 1, wherein the (A1) binder polymer and / or (A2) binder polymer is a polyamic acid. 2. The (A1) binder polymer and / or (A2) binder polymer is a polyamic acid using a polysiloxane diamine represented by the following general formula (1) as a part of a raw material. The photosensitive dry film resist of the multilayer structure of any one of -5.
(In the formula, each R ₁ independently represents a hydrocarbon having 1 to 5 carbon atoms, each R ₂ independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, n represents an integer of 1 to 20.) The (A1) binder polymer and / or (A2) binder polymer is represented by the following general formula (2):
(Wherein R ¹ represents a tetravalent organic group, R ² independently represents an alkylene group having 2 to 5 carbon atoms, R ³ independently represents a methyl group or a phenyl group, The phenyl group content in R ³ is 15% or more and 40% or less, and m is an integer of 4 or more and 20 or less.)
A structural unit represented by
The following general formula (3)
(In the formula, R ⁴ represents a tetravalent organic group, and R ⁵ represents a divalent organic group obtained by removing two amino groups from an aromatic diamine.)
6. The multilayer dry photosensitive dry film resist according to claim 1, wherein the polyamic acid comprises a structural unit represented by the formula: The polyamic acid is further represented by the following general formula (4):
(Wherein R ⁶ represents a tetravalent organic group, and R ⁷ represents the following chemical formulas a, b, c, d, e, f or g:
In the chemical formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in the chemical formula f, R ⁸ represents a hydrogen atom or a methyl group. Represents an ethyl group or a butyl group. )
The photosensitive dry film resist having a multilayer structure according to claim 9, comprising a structural unit represented by: The (A1) binder polymer and / or (A2) binder polymer is represented by the following general formula (4):
(Wherein R ⁶ represents a tetravalent organic group, and R ⁷ represents the following chemical formulas a, b, c, d, e, f or g:
In the chemical formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in the chemical formula f, R ⁸ represents a hydrogen atom or a methyl group. Represents an ethyl group or a butyl group. )
A structural unit represented by
The following general formula (3)
(In the formula, R ⁴ represents a tetravalent organic group, and R ⁵ represents a divalent organic group obtained by removing two amino groups from an aromatic diamine.)
6. The multilayer dry photosensitive dry film resist according to claim 1, wherein the polyamic acid comprises a structural unit represented by the formula: In the general formula (3), the structural unit represented by the general formula (3) is a group in which at least one of the aromatic rings to which the two amino groups of the aromatic diamine in R ⁵ are bonded is a meta group. The photosensitive dry film resist having a multilayer structure according to any one of claims 9 to 11, comprising a structural unit bonded to the main chain by two bonding hands located at positions.   The aromatic diamine is m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3′-diaminodiphenylsulfone, 3,3′-. Diaminobenzanilide, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) ) Phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) -Biphenyl, 1,3-bis (3-aminophenoxy) benzene, bis [4- (3-aminopheno) ) Phenyl] sulfone or 2,2-bis (3-aminophenyl) photosensitive dry film resist according to any one of claims 9-12, characterized in that propane,.   6. The multilayer structured photosensitivity according to any one of claims 1 to 5, wherein the (A1) binder polymer and / or (A2) binder polymer is a soluble polyimide having a carboxyl group and / or a hydroxyl group. Dry film resist. The (A1) binder polymer and / or (A2) binder polymer is a soluble polyimide having a carboxyl group and / or a hydroxyl group using the polysiloxane diamine represented by the general formula (1) as a part of the raw material. The photosensitive dry film resist having a multilayer structure according to any one of claims 1 to 5.
(In the formula, each R ₁ independently represents a hydrocarbon having 1 to 5 carbon atoms, each R ₂ independently represents an organic group selected from an alkyl group having 1 to 5 carbon atoms or a phenyl group, n represents an integer of 1 to 20.)   16. The multilayer dry photosensitive dry film resist according to claim 1, wherein the thickness of the first photosensitive layer is 100, and the thickness of the second photosensitive layer is 500 or less.   A printed wiring board, wherein the photosensitive dry film resist having a multilayer structure according to claim 1 is used as an insulating protective layer.   The structure in the photosensitive dry film resist, wherein the second photosensitive layer is located on the outermost layer in contact with the circuit surface, and the first photosensitive layer is located on the other outermost layer. 17. The printed wiring board according to 17.   A method for producing a printed wiring board, wherein the photosensitive dry film resist according to any one of claims 1 to 16 is cured at a temperature of 180 ° C. or less to form an insulating protective layer.