JP5378213B2 - Photosensitive dry film resist material, printed wiring board using the same, and method for manufacturing printed wiring board - Google Patents

Abstract

A photosensitive dry film resist material which can be developed with a water-based developer and is excellent in resolution, flame retardancy, adhesion, moisture resistance, and electrical reliability; a printed wiring board made with the material; and a process for producing the printed wiring board. The photosensitive dry film resist material (1) comprises a supporting film (2) and a photosensitive dry film resist (3) formed thereon, wherein the proportion of phosphorus atoms present in a surface (4) (surface in contact with the supporting film (2)) of the photosensitive dry film resist (3) is higher than the proportion of phosphorus atoms present in a surface (5) (surface on the side opposite to the surface (4)) of the photosensitive dry film resist (3).

Description

  The present invention relates to a photosensitive dry film resist material, a printed wiring board using the same, and a method for producing the printed wiring board, and in particular, water-based development is possible, and resolution, flame retardancy, adhesion, moisture resistance The present invention relates to a photosensitive dry film resist material excellent in reliability and 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 a printed wiring board substrate, formation of a protective layer for protecting the printed wiring board surface and pattern circuit, formation of an interlayer insulating layer of a 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 these workability and positional accuracy, a method of forming a protective layer by applying and drying a solution of a photosensitive resin composition on a 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, since a photomask is placed on the formed photosensitive dry film resist for exposure and development, 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 commercially available. However, a photosensitive dry film resist made of an acrylic resin has a problem that its heat resistance and mechanical strength of the film are not sufficient, so that its use is limited. Therefore, development of a technique for improving the flame retardancy of the photosensitive dry film resist and the mechanical strength of the film is underway. Specifically, a technology that improves the flame retardancy by adding a flame retardant to the photosensitive dry film resist, instead of an acrylic resin, polyimide having excellent heat resistance among various organic polymers was used. Technologies using photosensitive polyimide have been developed.

  More specifically, as a technique for improving flame retardancy by adding a flame retardant, for example, there is a photosensitive dry film resist produced by curing a photosensitive resin composition containing a brominated flame retardant (for example, , See 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. Specifically, the use of nitrogen-based flame retardants, phosphorus-based flame retardants, and the like as non-halogen-based flame retardants (for example, see Patent Document 2).

  Moreover, as a technique using photosensitive polyimide, for example, in Patent Documents 6 to 9, a photosensitive polyimide mixed with a polyamic acid and a (meth) acrylic compound is used as a dry film for an FPC coverlay material. It is described that it is used as a photosensitive resin composition for producing the above. Further, in 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 in terms of work safety, exposure It is described that the subsequent film is sufficiently cured and exhibits high extensibility.

  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).

  In addition, as a photosensitive polyimide, the thing of the various composition was examined until now mainly for the purpose of using for a semiconductor use, and a tertiary amine and (meth) acryloyl group were used for the polyamic acid (polyimide precursor). An ion-bonded photosensitive polyimide obtained by mixing a compound having a photo-sensitive polyimide, an ester-bonded photosensitive polyimide in which a methacryloyl group is introduced into a carboxyl group of a polyamic acid via an ester bond, and an isocyanate having a methacryloyl group A photosensitive polyimide obtained by introducing a compound into a carboxyl group portion of a polyamic acid (polyimide precursor), a photosensitive polyimide obtained by mixing a polyamic acid and a (meth) acrylic compound, and the like have been reported.

By the way, although it is not the technique concerning a photosensitive dry film resist, in patent document 3, the structure which provides two or more coating layers which coat | cover this on a conductor circuit is described in a printed wiring board. In the printed wiring board, the coating layer in contact with the conductor circuit is an insulating layer having an insulation resistance of 1 × 10 ¹⁰ Ω or more, made of an insulating ink mainly composed of polyester resin. The outermost coating layer is made of a flame retardant ink containing a polyester resin and a non-halogen flame retardant. Melamine cyanurate, magnesium hydroxide, and aluminum hydroxide are used as the non-halogen flame retardant. In Patent Document 4, a base layer on which a conductor is formed is a composite layer in which at least a first resin layer having moisture resistance and a second resin layer containing a non-halogen flame retardant are laminated. The resin composition covered with is described. As the non-halogen flame retardant, a phosphorus flame retardant containing a phosphate ester or a phosphate is described. Note that none of these relates to a photosensitive film and does not support fine processing.

  In addition, as a photosensitive film having a multilayer structure, for example, Patent Document 5 discloses a first photosensitive layer containing a binder, a polymerizable compound and a photopolymerization initiator on a support, a barrier layer containing a polymerizable compound, and a binder. And a photosensitive transfer sheet in which a second photosensitive layer containing a polymerizable compound and a photopolymerization initiator and having a photosensitivity relatively higher than the photosensitivity of the first photosensitive layer is laminated in this order. In such a photosensitive transfer sheet, it is described that desired patterns having different thicknesses can be easily formed in an image. In Patent Document 5, the purpose is to improve the photosensitive characteristics, and it is not intended to improve the flame retardancy, moisture resistance, and electrical reliability.

  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.

  Specifically, when improving flame retardancy with a flame retardant, use of a nitrogen-based compound as the flame retardant affects the curability of the resin, making it difficult to put it to practical use. Further, as in Patent Document 2, if a phosphorus-based flame retardant is used, flame retardancy can be achieved, but the moisture resistance of the photosensitive resin composition tends to increase, so that the moisture resistance decreases, Has a problem that the electrical reliability is lowered.

  Moreover, in the photosensitive resin composition which mixed the polyamic acid and the (meth) acrylic-type compound described in patent document 6-patent document 9, the coverlay film and base film which are obtained from this photosensitive resin composition, It is difficult to suppress the warpage caused by the mismatch with the thermal expansion coefficient. In the FPC, a copper foil pattern is usually drawn on a thin base film (about 25 μm) directly or via an adhesive. The coverlay film is formed on the surface of the copper foil pattern 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.

  Furthermore, in the photosensitive resin composition using the polyamic acid obtained from the polysiloxane diamine described in Patent Document 10 as a raw material and a (meth) acrylic compound, 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. Therefore, there is a problem that the electrical reliability is inferior.

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 is nothing that satisfies all of the characteristics and low warpage.
Japanese Patent Laying-Open No. 2004-219690 (released on August 5, 2004) 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)

  The present invention has been made in view of the above-mentioned problems, and its purpose is a photosensitive dry film resist capable of aqueous development and having excellent resolution, flame retardancy, adhesion, moisture resistance, and electrical reliability. The object is to provide a material, a printed wiring board using the same, and a method of manufacturing the same.

  As a result of intensive studies in view of the above-mentioned problems, the present inventors have found that a photosensitive dry film resist material provided with a photosensitive dry film resist on a support film, the surface of the photosensitive dry film resist in contact with the support film. By making the abundance ratio of phosphorus atoms larger than the abundance ratio of phosphorus atoms on the surface located behind the surface, aqueous development is possible, and resolution, flame retardancy, adhesion, moisture resistance, and electrical reliability are possible. The inventors have uniquely found that a photosensitive dry film resist material excellent in the above can be realized, and have completed the present invention. That is, the present invention includes the following industrially useful inventions.

  (1) A photosensitive dry film resist material comprising a support film and a photosensitive dry film resist, wherein the photosensitive dry film resist is disposed on the support film, and the photosensitive dry film The resist has a first surface in contact with the support film and a second surface located behind the first surface, and the abundance ratio of phosphorus atoms in the second surface is the presence of phosphorus atoms in the first surface. A photosensitive dry film resist material characterized by being smaller than the ratio.

  (2) In the photosensitive dry film resist, the abundance ratio of phosphorus atoms in the second region from the second surface to a depth of 2 μm is higher than the abundance ratio of phosphorus atoms in the first region from the first surface to a depth of 2 μm. The photosensitive dry film resist material according to (1), wherein the abundance ratio of phosphorus atoms in the second region is 70% or less of the abundance ratio of phosphorus atoms in the first region.

  (3) The abundance ratio of phosphorus atoms in the first region is 0.05 to 0.4, and the abundance ratio of phosphorus atoms in the second region is 0 to 0.08 ( The photosensitive dry film resist material as described in 2).

  (4) The photosensitive dry film resist according to any one of (1) to (3), wherein a phosphorus atom concentration gradient is formed between the first surface and the second surface. The photosensitive dry film resist material described.

  (5) The photosensitive dry film resist material according to any one of (1) to (4), wherein a protective film is further provided on the photosensitive dry film resist.

  (6) The photosensitive dry film resist has a multilayer structure including at least a first photosensitive layer including the first surface and a second photosensitive layer including the second surface, and the first photosensitive layer includes: A1) a binder polymer, (B1) a (meth) acrylic compound, (C1) a photoreaction initiator, and (D1) a phosphorus flame retardant as essential components, and the second photosensitive layer comprises (A2) a binder polymer And (B2) a (meth) acrylic compound as an essential component, wherein the second photosensitive layer does not substantially contain (D2) a phosphorus-based flame retardant (1) to (5) The photosensitive dry film resist material according to any one of the above.

  (7) The photosensitive dry film resist material according to (6), wherein the thickness of the first photosensitive layer is 1/5 or more of the thickness of the second photosensitive layer.

  (8) A printed wiring board using the photosensitive dry film resist of the photosensitive dry film resist material according to any one of (1) to (7) as an insulating protective layer.

  (9) The printed wiring board according to (8), wherein the second surface and the circuit surface are in contact with each other.

  (10) The photosensitive dry film resist material according to any one of (1) to (7), wherein the photosensitive dry film resist is cured at a temperature of 180 ° C. or less and used as an insulating protective layer. A method for manufacturing a wiring board.

  As described above, the photosensitive dry film resist material according to the present invention has the photosensitive dry film resist disposed on the support film. Therefore, the contact surface of the photosensitive dry film resist with the support film can be prevented from being contaminated by impurities in the air. The photosensitive dry film resist has a first surface in contact with the support film and a second surface located on the back side of the first surface, and the abundance ratio of phosphorus atoms in the second surface is as described above. It is smaller than the abundance ratio of phosphorus atoms on the first surface. Therefore, the photosensitive dry film resist material according to the present invention has excellent water-based developability and excellent effects of flame retardancy, adhesion, moisture resistance, and electrical reliability.

  Other objects, features, and advantages of the present invention will be fully understood from the following description. The benefits of the present invention will become apparent from the following description with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a photosensitive dry film resist material according to this embodiment. FIG. 2 is a diagram showing the results of elemental analysis in the first region of the photosensitive dry film resist material according to the present embodiment. FIG. 3 is a diagram showing the results of elemental analysis in the second region of the photosensitive dry film resist material according to the present embodiment. FIG. 4 is a schematic diagram showing a comb pattern (line / space = 100 μm / 100 μm) formed on a flexible copper-clad laminate in the method for evaluating the electrical reliability of the example. FIG. 5 is a schematic diagram showing a comb pattern (line / space = 25 μm / 25 μm) formed on a flexible copper-clad laminate in the method for evaluating the electrical reliability of the example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive dry film resist material 2 Support film 3 Photosensitive dry film resist 4 Surface (1st surface)
5 Surface (2nd surface)
6 areas (first area)
7 area (2nd area)

  An embodiment according to the present invention will be specifically described below with reference to FIGS. 1 to 3, but the present invention is not limited to this.

<I. Photosensitive dry film resist material>
The photosensitive dry film resist material 1 shown in FIG. 1 will be described as an embodiment of the photosensitive dry film resist material according to the present invention. However, the photosensitive dry film resist material according to the present invention is not limited to this. Absent. As shown in FIG. 1, the photosensitive dry film resist material 1 is a photosensitive dry film resist material in which a photosensitive dry film resist 3 is provided on a support film 2. The photosensitive dry film resist 3 has a surface 4 (first surface) in contact with the support film 2 and a surface 5 (second surface) located on the back side of the surface 4. In the photosensitive dry film resist 3, the abundance ratio of phosphorus atoms is different between the surface 4 and the surface 5. Specifically, the abundance ratio of phosphorus atoms on the surface 5 is smaller than the abundance ratio of phosphorus atoms on the surface 4. More specifically, the abundance ratio of phosphorus atoms on the surface 5 is preferably 70% or less of the abundance ratio of phosphorus atoms on the surface 4.

  According to the said structure, the photosensitive dry film resist 3 can be made into the photosensitive dry film resist which is excellent in water-system developability, and is excellent in a flame retardance, adhesiveness, moisture resistance, and electrical reliability. Moreover, since the photosensitive dry film resist material 1 includes the support film 2, it is possible to prevent impurities in the air from adhering to the surface 4.

  In the photosensitive dry film resist 3, the abundance ratio of phosphorus atoms on the surface 5 is preferably substantially zero. Thereby, the water-based developability, flame retardancy, adhesion, moisture resistance, and electrical reliability of the photosensitive dry film resist 3 can be further improved.

  In this specification, “the abundance ratio of phosphorus atoms is substantially 0” means that, in addition to the abundance ratio of phosphorus atoms being 0, (1) in analysis, the detection sensitivity is below the detection sensitivity (noise level). In some cases, (2) a trace amount of phosphorus atoms is detected even though the actual abundance ratio of phosphorus atoms is 0 due to analytical problems, and (3) a very small amount of phosphorus atoms may be included. Intended. Further, in this specification, “the abundance ratio of phosphorus atoms on the surface 4 or the surface 5” represents a ratio of phosphorus atoms to carbon atoms on the surface 4 or the surface 5. The abundance ratio of phosphorus atoms on the surface 4 or the surface 5 is a chemical composition that forms the surface 4 or the surface 5 and / or a method for analyzing the abundance ratio of phosphorus atoms in the region from the surface 4 or the surface 5 to a depth of 2 μm described later. Can be evaluated based on

  The phosphorus atom contained in the photosensitive dry film resist 3 is preferably a phosphorus atom derived from a phosphorus flame retardant. In this case, in the above configuration, the surface 4 contains more phosphorus-based flame retardant than the surface 5, and preferably, the surface 5 does not substantially contain the phosphorus-based flame retardant. Therefore, the moisture resistance and electrical reliability of the photosensitive dry film resist 3 can be further improved. Furthermore, according to the said structure, since it becomes difficult to generate | occur | produce a residue at the time of alkali image development, the developability and resolution of the photosensitive dry film resist 3 can be improved more.

  In the photosensitive dry film resist 3, the region 7 (second region) from the surface 5 to 2 μm in depth is larger than the abundance ratio of phosphorus atoms in the region 6 (first region; see FIG. 1) from the surface 4 to 2 μm in depth. The abundance ratio of phosphorus atoms in the region (see FIG. 1) is preferably smaller. Specifically, the phosphorus atom abundance ratio in the region 7 is preferably 70% or less, more preferably 60% or less, of the phosphorus atom abundance ratio in the region 6. Furthermore, the abundance ratio of phosphorus atoms in the region 6 is preferably 0.05 to 0.4, and more preferably 0.05 to 0.3. The abundance ratio of phosphorus atoms in the region 7 is preferably 0 to 0.08, and more preferably substantially 0. If the abundance ratio of phosphorus atoms in the region 6 and the region 7 is within the above range, the photosensitive dry film resist 3 has good water-based developability, and has flame retardancy, adhesion, moisture resistance, and electrical reliability. An excellent photosensitive dry film resist can be obtained.

  In this specification, “the abundance ratio of phosphorus atoms in the region 6 or the region 7” represents the ratio of phosphorus atoms to carbon atoms in the region 6 or the region 7. Here, an analysis (evaluation) method of the “abundance ratio of phosphorus atoms in the region 6 or the region 7” will be described in detail with reference to FIG.

  In the analysis of “abundance ratio of phosphorus atoms in region 6 or region 7”, first, the photosensitive dry film resist material 1 is cut perpendicularly to the surface 4 and the surface 5 using an ultramicrotome / diamond knife. Then, a section having a cross section perpendicular to the surface 4 and the surface 5 (see FIG. 1) is cut out. Thereafter, the section is fixed on carbon tape. Elemental analysis is performed on a section fixed on the carbon tape, in other words, a cross section perpendicular to the surface 4 and the surface 5 of the photosensitive dry film resist material 1. Elemental analysis is performed using a scanning electron microscope-X-ray microanalyzer (Hitachi S-3000N HORIBA EMAX-7000). The analysis conditions are an acceleration voltage of 15 kV and a measurement time of 100 seconds.

  As shown in FIG. 1, the region for elemental analysis is a region 8 of 2 μm square (in other words, a square having a side of 2 μm) in the region 6 in the analysis of the abundance ratio of phosphorus atoms in the region 6. The area | region 8 should just be 2 micrometers square, and is an arbitrary area | region in the area | region 6. FIG. Similarly, in the analysis of the abundance ratio of phosphorus atoms in the region 7, the region 9 in the region 7 is a 2 μm square (in other words, a square having a side of 2 μm). The region 9 only needs to be 2 μm square, and is an arbitrary region in the region 7.

  Next, with respect to data obtained by elemental analysis of the region 8 (see, for example, Example 1 (FIG. 2) described later), the phosphorus signal intensity and the carbon signal intensity are calculated, and the phosphorus signal intensity is calculated. Is divided by the signal intensity of the carbon. The value thus obtained is defined as the abundance ratio of phosphorus atoms in the region 6. Similarly, with respect to data obtained by elemental analysis of the region 9 (see, for example, Example 2 (FIG. 3) described later), the signal intensity of phosphorus and the signal intensity of carbon are calculated, and the signal intensity of the phosphorus Is divided by the signal intensity of the carbon. The value thus obtained is defined as the abundance ratio of phosphorus atoms in the region 7.

  In the method for analyzing the abundance ratio of phosphorus atoms, when the photosensitive dry film resist material 1 is cut using an ultramicrotome / diamond knife, the regions 6 and 7 are contaminated by phosphorus existing in other regions. May be. Further, the region 8 and the region 9 may be slightly shifted depending on the measurement accuracy of the measurement device used for elemental analysis, the specification of the device, and the like. Therefore, the preferable numerical range for the abundance ratio of phosphorus atoms in the region 6 and the region 7 has been described above. However, when such an error occurring in the analysis is taken into consideration, it is determined that it is substantially included in the numerical range. Is included in the scope of the present invention.

  In the photosensitive dry film resist 3, a phosphorus atom concentration gradient may be formed between the surface 4 and the surface 5. Specifically, a gradient is preferably formed from the surface 5 toward the surface 4 so that the concentration of phosphorus atoms increases. In addition, this invention is not limited to this, Between the surface 4 and the surface 5, the area | region where the abundance ratio of a phosphorus atom is lower than the surface 5 may exist, or the abundance ratio of a phosphorus atom rather than the surface 4 There may be regions with high. Further, the concentration gradient of the phosphorus atom may be a linear gradient, a curved gradient, or a stepwise gradient. Further, such a concentration gradient of phosphorus atoms may be formed by forming the photosensitive dry film resist 3 into a multilayer structure of two layers or more. Specifically, in the resin composition of each layer constituting the multilayer structure, the phosphorus atom concentration gradient may be formed by adjusting the abundance ratio of phosphorus atoms as desired.

  The photosensitive dry film resist material 1 may further include a protective film (not shown) on the photosensitive dry film resist 3. With such a configuration, it is possible to prevent dust and dust in the air from adhering to the surface 5 and to prevent deterioration of quality due to drying of the photosensitive dry film resist 3.

  Hereinafter, although the support film 2, the photosensitive dry film resist 3, and the protective film will be described more specifically, the present invention is not limited to these.

(I-1) Support Film The support film 2 is a film for supporting the photosensitive dry film resist 3. The material is not particularly limited. Specifically, various commercially available films such as a polyethylene terephthalate (PET) film, a polyphenylene sulfide film, and a polyimide film can be used. As the support film 2, a PET film is often used because it has a certain degree of heat resistance and is relatively inexpensive. In addition, the surface treatment for improving the adhesiveness and peelability of the support film 2 and the photosensitive dry film resist 3 may be performed on the surface in contact with the surface 4 of the support film 2.

(I-2) Photosensitive Dry Film Resist As described above, the photosensitive dry film resist 3 only needs to have a phosphorus atom abundance ratio on the surface 5 smaller than a phosphorus atom abundance ratio on the surface 4. It is preferable that the abundance ratio of phosphorus atoms in 5 is substantially 0. Furthermore, the abundance ratio of phosphorus atoms in the region 7 is preferably 70% or less, more preferably 60% or less of the abundance ratio of phosphorus atoms in the region 6. Further, the abundance ratio of phosphorus atoms in the region 6 is preferably 0.05 to 0.4, and more preferably 0.05 to 0.3. Furthermore, the abundance ratio of the phosphorus atoms in the region 7 is preferably 0 to 0.08, and more preferably substantially 0.

  The specific layer structure and chemical composition of the photosensitive dry film resist 3 are not particularly limited as long as the above conditions are satisfied. That is, the photosensitive dry film resist 3 may have a single-layer structure, a two-layer structure, a three-layer structure, or a multilayer structure of four or more layers. Good.

  Although the thickness of the photosensitive dry film resist 3 is not specifically limited, For example, it is preferable that they are 5 micrometers-75 micrometers, and it is more preferable that they are 10 micrometers-60 micrometers. When the thickness of the photosensitive dry film resist 3 is less than 5 μm, it may be impossible to cover a conductor wiring such as copper. On the other hand, if the thickness of the photosensitive dry film resist 3 is larger than 75 μm, the photosensitivity may be lowered. However, within the above range, conductor wiring such as copper can be reliably coated and the photosensitivity is not lowered.

  One embodiment of the photosensitive dry film resist 3 will be described more specifically below, but the present invention is not limited to this.

  In this embodiment, the photosensitive dry film resist 3 has a multilayer structure including at least a first photosensitive layer including the surface 4 and a second photosensitive layer including the surface 5.

  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 3 tends to decrease. On the other hand, 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 be lowered. Therefore, according to the said structure, it can be set as the photosensitive dry film resist excellent in a flame retardance and electrical reliability.

  Assuming that the thickness of the first photosensitive layer is 100, the flame retardancy of the photosensitive dry film resist 3 may be reduced if the thickness of the second photosensitive layer is greater than 500. Further, assuming that 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 be lowered. However, within the above range, both the flame retardancy and electrical reliability of the photosensitive dry film resist 3 can be improved.

  The first photosensitive layer contains (A1) a binder polymer, (B1) (meth) acrylic compound, (C1) a photoreaction initiator, and (D1) a phosphorus flame retardant as essential components. On the other hand, the second photosensitive layer contains (A2) a binder polymer and (B2) (meth) acrylic compound as essential components. In addition to the above components, the first photosensitive layer may contain (E1) other components as necessary. Moreover, it is preferable that the said 2nd photosensitive layer contains (C2) photoreaction initiator in addition to the said component. Further, similarly to the first photosensitive layer, it may contain (E2) other components as required. In addition, although the said 2nd photosensitive layer may contain (D2) phosphorus flame retardant, it is preferable not to contain substantially. Thereby, the moisture resistance of the photosensitive dry film resist 3 and electrical reliability can be improved more. Furthermore, according to the said structure, when bonding the photosensitive dry film resist 3 to a circuit board, the 2nd photosensitive layer which contact | connects a circuit surface is excellent in alkali solubility. Therefore, a residue hardly occurs during alkali development, and developability and resolution can be further improved. Therefore, it is possible to prevent a decrease in electrical reliability, a decrease in alkali solubility, and generation of a residue. In many cases, the residue is generated at the interface with the substrate having a strong interaction. Therefore, if the alkali solubility of the second photosensitive layer in contact with the substrate is excellent, a residue is hardly generated even if the alkali solubility of the first photosensitive layer is inferior.

  Here, the content of each component in the first photosensitive layer and the second photosensitive layer of the photosensitive dry film resist 3 will be described.

  First, in the first photosensitive layer, the content of the (A1) binder polymer is preferably 10% by weight to 90% by weight, and 20% by weight to 85% by weight with respect to the total weight of the first photosensitive layer. It is more preferable that it is 25 wt% to 80 wt%. Similarly, in the second photosensitive layer, the content of the (A2) binder polymer is preferably 10% by weight to 90% by weight, and preferably 20% by weight to 85% with respect to the total weight of the second photosensitive layer. More preferably, it is 25 weight%, and it is further more preferable that it is 25 weight%-80 weight%. Thus, when the content of the binder polymer in the first photosensitive layer and the second photosensitive layer is 10% by weight or more, the heat resistance of the first photosensitive layer and the second photosensitive layer can be improved. Further, when the content is 90% by weight or less, it is possible to perform pressure bonding on the base material at a low temperature.

  Next, in the first photosensitive layer, the content of the (B1) (meth) acrylic compound is preferably 1 part by weight to 400 parts by weight with respect to 100 parts by weight of the (A1) binder polymer. More preferably, it is 3 to 300 parts by weight. Similarly, in the second photosensitive layer, the content of (B2) (meth) acrylic compound is preferably 1 part by weight to 400 parts by weight with respect to 100 parts by weight of the (A2) binder polymer. More preferably, it is 3 to 300 parts by weight. By setting the content of the (meth) acrylic compound in the first photosensitive layer and the second photosensitive layer within the above range, the first photosensitive layer and the second photosensitive layer are effective at a lower temperature than conventional ones. Can be imidized.

  In the first photosensitive layer and the second photosensitive layer, the contents of (C1) photoreaction initiator and (C2) photoreaction initiator are not particularly limited, and a sensitizing effect is obtained and development is performed. What is necessary is just to mix | blend in the range which does not have a bad influence on property. Specifically, in the first photosensitive layer, the content of the (C1) photoreaction initiator is 0.01 to 50 parts by weight with respect to 100 parts by weight of the (A1) binder polymer. preferable. Similarly, in the second photosensitive layer, the content of (C2) photoreaction initiator is preferably 0.01 to 50 parts by weight with respect to 100 parts by weight of (A2) binder polymer.

  As long as the content of the photoreaction initiator in the first photosensitive layer is within the above range, even if the second photosensitive layer does not contain the (C2) photoreaction initiator, the photosensitivity having a certain resolution and photosensitivity. The conductive dry film resist 3 can be formed. Therefore, as another embodiment, the second photosensitive layer may be substantially free of (C2) a photoreaction initiator. Here, “the second photosensitive layer substantially does not contain (C2) photoinitiator” means that the second photosensitive layer does not contain (C2) photoinitiator at all or is slightly contained. It is intended to be a quantity. Specifically, the content of the (C2) photoinitiator in the second photosensitive layer is intended to be 0 to 0.01 parts by weight with respect to 100 parts by weight of the (A2) binder polymer. Is done.

  Furthermore, 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. Specifically, in the first photosensitive layer, the content of the flame retardant (D1) is determined when the total amount of the (A1) binder polymer and the (B1) (meth) acrylic compound is 100 parts by weight. It is preferably 1 part by weight to 50 parts by weight, more preferably 5 parts by weight to 40 parts by weight, further preferably 10 parts by weight to 40 parts by weight, and 10 parts by weight to 30 parts by weight. Most preferably it is. If the content of the flame retardant in the first photosensitive layer is less than 1 part by weight, a sufficient flame retardant effect may not be obtained. On the other hand, if the content exceeds 50 parts by weight, the physical properties of the cured product, for example, the mechanical properties of the photosensitive dry film resist 3 after curing may be adversely affected. However, within the above range, sufficient flame retardancy can be imparted without adversely affecting the mechanical properties of the photosensitive dry film resist 3 after curing.

  On the other hand, although the said 2nd photosensitive layer may contain (D2) phosphorus flame retardant, it is preferable not to contain substantially. Here, “the second photosensitive layer substantially does not contain (D2) a phosphorus-based flame retardant” means that the second photosensitive layer does not contain (D2) a flame retardant at all or is slightly contained. Is intended. Specifically, in the second photosensitive layer, the content of the flame retardant (D2) is 0% by weight to 10% by weight, preferably 0% by weight to 5% by weight, based on the total weight of the second photosensitive layer. More preferably, it is intended to be 0% to 1% by weight.

  Hereinafter, the bainter polymer, the (meth) acrylic compound, the photoreaction initiator, the phosphorus flame retardant, and other components contained in the first photosensitive layer and the second photosensitive layer will be specifically described.

(I-2-1) Binder polymer In this specification, “binder polymer” is used to impart film-forming ability to the photosensitive resin composition used to form the photosensitive dry film resist 3. The polymer component to be blended is contemplated. 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 is not particularly limited, but is desirably soluble in an aqueous alkali solution or swellable in order to enable aqueous development, so that a carboxyl group, a hydroxyl group, a sulfonic acid group, phosphoric acid is present in the polymer chain. It preferably contains an acidic functional group such as a 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.

  Among the binder polymers, according to the carboxyl group-containing vinyl polymer, the photosensitive dry film resist 3 can be a photosensitive dry film resist excellent in flexibility and alkali solubility. Furthermore, since such a carboxyl group-containing vinyl polymer is easy to manufacture, the photosensitive dry film resist material 1 can be manufactured at a low cost. In addition, according to the polyamic acid, the photosensitive dry film resist 3 as a whole has excellent characteristics such as aqueous developability, flame retardancy, adhesion, moisture resistance, electrical reliability, and solder heat resistance. be able to. Furthermore, according to the soluble polyimide having a carboxyl group and / or a hydroxyl group, flame resistance and heat resistance can be imparted to the photosensitive dry film resist 3. Furthermore, since such a soluble polyimide has already been imidized, it is possible to set the temperature of the heat curing low or to set the time short. Therefore, the productivity of the photosensitive dry film resist material 1 according to the present invention can be improved.

  These binder polymers having an acidic functional group may be used alone or in combination. In the present invention, the (A1) binder polymer contained in the first photosensitive layer and the (A2) binder polymer contained in the second photosensitive layer may be the same or different.

  Hereinafter, as a binder polymer contained in the photosensitive dry film resist 3, a carboxyl group-containing vinyl polymer, a polyamic acid, a soluble polyimide having a carboxyl group and / or a hydroxyl group will be described. The binder polymer contained in the photosensitive dry film resist 3 is not limited to these.

[Carboxyl group-containing vinyl polymer]
The carboxyl group-containing vinyl polymer is not particularly limited, and any one can be used as long as it is a copolymer of a carboxyl group-containing monomer and a monomer copolymerizable with the carboxyl group-containing monomer.

  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, and phthalic anhydride. Etc. Among these, (meth) acrylic acid is preferable from the viewpoints of cost, polymerizability, and the like. These are used alone or in combination of two or more.

  Examples of the monomer copolymerizable with the carboxyl group-containing monomer include (meth) acrylic acid esters, maleic acid diesters, fumaric acid diesters, crotonic acid esters, vinyl esters, maleic acid diesters, (meta ) 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 are used alone or in combination of two or more.

  In the carboxyl group-containing vinyl polymer, the content of the carboxyl group-containing monomer is not particularly limited, but specifically, it is preferably 5 mol% to 50 mol%, and preferably 15 mol% to 40 mol%. More preferably. 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.

  Further, the weight average molecular weight of the carboxyl group-containing vinyl polymer is not particularly limited, but is preferably 5000 to 300000, and more preferably 10000 to 200000. If the weight average molecular weight is less than 5,000, the photosensitive dry film resist 3 tends to be sticky, and further tends to be inferior in the bending resistance of the cured film. On the other hand, if the weight average molecular weight is larger than 300,000, the developability of the produced photosensitive dry film resist 3 may be lowered. The weight average molecular weight can be measured by size exclusion chromatography (SEC), for example, HLC8220GPC manufactured by Tosoh Corporation.

[Polyamide acid]
The polyamic acid is a compound obtained by reacting acid dianhydride and diamine in an organic solvent. The weight average molecular weight of the polyamic acid is not particularly limited, but is preferably 2,000 to 1,000,000, more preferably 5,000 to 300,000, and further preferably 10,000 to 200,000. When the weight average molecular weight of the polyamic acid is 2000 or more, the strength of the photosensitive dry film resist 3 is not lowered. Further, when the weight average molecular weight is 5000 or more, the photosensitive dry film resist 3 is not sticky, and the cured film is not inferior in bending resistance. On the other hand, if the weight average molecular weight is 1000000 or less, it is possible to suppress an increase in the development time of the photosensitive dry film resist 3. Furthermore, if the weight average molecular weight is 300000 or less, the solution viscosity will not be too high and handling will not be difficult, and the developability of the produced photosensitive dry film resist 3 will not be reduced. The weight average molecular weight can be measured by size exclusion chromatography (SEC), for example, HLC8220GPC manufactured by Tosoh Corporation.

  More specifically, regarding the structure of the polyamic acid contained in the first photosensitive layer and the second photosensitive layer, the diamine is represented by the following general formula (1).

(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.)
It is preferable that it is a polyamic acid using the polysiloxane diamine represented by these as at least one part of a raw material. Such polyamic acid can improve the flexibility, adhesion, and flexibility of the photosensitive dry film resist 3. Therefore, it is possible to realize a photosensitive dry film resist having excellent developability, resolution, flame retardancy, adhesion, moisture resistance, and electrical reliability and also having low warpage.

  Furthermore, by using a polyamic acid made of a polysiloxane diamine having a certain structure as a raw material, the flame retardancy of the polyimide itself can be improved and a low imidization temperature can be realized. With such polyamic acid, developability with an aqueous developer; excellent resolution, flame retardancy, adhesion, moisture resistance, electrical reliability, and low warpage; and photosensitivity that satisfies all of the low imidization temperatures. A functional dry film resist can be realized.

  Thus, it is preferable that the polyamic acid contained in the photosensitive dry film resist 3 is a polyamic acid having a good balance between flame retardancy and flexibility. Specifically, the following general formula (2)

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

  By including such polyamic acid, aqueous 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. it can.

In the general formula (2), R ¹ is not particularly limited, but is preferably a tetravalent organic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, and these 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 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.

Moreover, in General formula (2), R < ³ > is a methyl group or a phenyl group each independently. The methyl group in R ³ is a property of the resulting polyamic acid, the photosensitive dry film resist containing the polyamic acid, and the imidized product thereof (hereinafter, these three are collectively referred to as “polyamic acid etc.”). 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% to 40%, more preferably 18% to 38%, and even more preferably 20% to 35%. By setting the content of the phenyl group in R ³ to 15% or more, flame retardancy such as polyamic acid can be further improved. On the other hand, when the phenyl group content is higher than 40%, the flexibility and low warpage of the resulting polyamic acid and the like tend to decrease.・ Low warpage does not decrease. Therefore, by making the content of the phenyl group within the above range, a photosensitive dry film resist with less warpage, excellent flexibility, flexibility, electrical reliability, and photosensitivity and flame retardancy is realized. be able to.

  Moreover, according to the said structure, since a flame retardance improves, compared with the photosensitive dry film resist using the polyamic acid obtained using the conventional polysiloxane diamine, content of a flame retardant is reduced. Can do. Therefore, a photosensitive dry film resist that is more excellent in terms of flame retardancy, moisture resistance, and electrical reliability can be obtained.

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 methyl group content in R ³ is preferably 60% to 85%, more preferably 62% to 82%, and even more preferably 65% to 80%. By setting the content of the methyl group in R ³ to 60% or more, the flexibility and low warpage of the resulting polyamic acid can be further improved. On the other hand, if the methyl group content is higher than 85%, the flame retardancy of the resulting polyamic acid or the like tends to decrease, but if it is 85% or less, such a flame retardancy may occur. Absent.

  Moreover, in General formula (2), the repeating unit number m of a siloxane bond is 4-20, Preferably it is 4-18, More preferably, it is an integer of 5-15. When m is 4 or more, the flexibility and low warpage of the polyamic acid obtained can be further improved. On the other hand, when m is larger than 20, polysiloxane sites aggregate in the resulting polyamic acid and the like, the aggregated domain becomes longer than the wavelength of visible light, light is diffusely reflected and whitened, and the photosensitivity may be lowered. Moreover, if a large domain of only polysiloxane is formed, flame retardancy may be reduced. However, if m is 20 or less, such a problem does not occur. Therefore, when m is in the above range, a photosensitive dry film resist having small warpage, excellent flexibility, flexibility, electrical reliability, and photosensitivity and flame retardancy can be realized.

In the general formula (3), R ⁴ is not particularly limited, but is preferably a tetravalent organic group, and is a monocyclic aromatic group, a condensed polycyclic aromatic group, and It is more preferable that two or more of these aromatic groups are tetravalent aromatic groups having 6 to 50 carbon atoms selected from groups 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 the general formula (3), R ⁵ is not particularly limited, but is preferably 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, R5 is a monocyclic aromatic group, a condensed polycyclic aromatic group, and a group having 6 to 6 carbon atoms selected from a group in which two or more of these aromatic groups are connected directly or by a connecting group. More preferably, it is a 50 divalent aromatic group. 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 a meta position. It is more preferable to include a structural unit bonded to the main chain with two bonds located at. For example, in the case where the aromatic diamine is phenylenediamine, such a structural unit is a single benzene ring to which two amino groups are bonded with two bonds located at the meta position. A structural unit bonded to the main chain. That is, in such a case, the aromatic diamine is m-phenylenediamine, and R ⁵ 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 R ⁵ is from 3,3′- or 3,4′-diaminodiphenylmethane to 2 It is a divalent group excluding an amino group.

  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. That is, according to the said structure, it becomes possible to manufacture the printed wiring board which hardened the photosensitive dry film resist 3 at the temperature of 180 degrees C or less, and was used as 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.

  The conventional photosensitive polyimide has been studied mainly for semiconductor applications. In semiconductor applications, there is no problem even if the temperature of imidization is high. For this reason, no investigation has been made on lowering the imidization temperature. That is, the conventional photosensitive polyimide is obtained by imidizing at a temperature of 300 ° C. or higher after exposure and development in a polyamic acid state. When such a photosensitive polyimide that imidizes at a high temperature is used as a photosensitive dry film resist for FPC, heat of 250 ° C. or higher is applied to the FPC itself. In general, epoxy resin or the like is used as a constituent material for rigid and flexible printed circuit boards, but these resins have lower heat resistance than polyimide and have only heat resistance of 200 ° C. or lower. Therefore, when conventional photosensitive polyimide that is cured at a high temperature of 300 ° C. or higher is used for FPC applications, there is a problem that the copper foil is oxidized or the crystal structure of copper is changed due to the high temperature and the strength of the copper foil is lowered. Occur. Therefore, conventional photosensitive polyimide cannot be used for rigid and flexible printed circuit boards. The polyamic acid used in the present invention is a polyamic acid that achieves an imidization ratio of 95% or more by heating at 180 ° C. or lower. Therefore, it is possible to manufacture a printed wiring board that is used as an insulating protective layer by curing the photosensitive dry film resist 3 at a temperature of 180 ° C. or lower.

  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%. In addition, when only m-phenylenediamine is used as the aromatic diamine used for producing 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 not particularly limited, but is a diamino compound in which an amino group is directly bonded to an aromatic ring and the amino group position is 3- or m-. Preferably there is. Specific examples include, for example, m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfone. 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] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane 1,4-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) -bif Nyl, n, 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-hydroxyphenyl] hexafluoropropane, 3,3′-diamino -4,4'-dihydroxydiphenyl ether, 3,3'-diamino-4,4'-dihydroxydiphenyl sulfone Bis [(hydroxyphenoxy) phenyl] sulfone such as bis [4- (3-amino-4-hydroxyphenoxy) 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'-dicarboxydiphenylsulfone, diamine compounds such as 3,5-diaminobenzoic acid be able to. In this case, the structural unit represented by the general formula (3) has a structure in which R5 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.

  In the first photosensitive layer and the second photosensitive layer, the polyamic acid contained as a binder polymer is a structural unit represented by the general formula (2) and a structural unit represented by the general formula (3). In addition to the following general formula (4)

(Wherein R ⁶ represents a tetravalent organic group, and R ⁷ represents the following chemical formula group (5)

(In Chemical Formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in Chemical Formula f, R ⁸ represents a hydrogen atom, a methyl group, an ethyl group, or a butyl group. .)
A, b, c, d, e, f or g. )
You may have the structural unit represented by these.

In general formula (4), R ⁶ is not particularly limited, but is preferably a tetravalent organic group, and is a monocyclic aromatic group, a condensed polycyclic aromatic group, and these 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 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 including the structural unit represented by the general formula (4), compatibility with the (meth) acrylic compound can be improved.

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. If 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 the conventional photosensitive dry film resist. It is possible to realize a photosensitive dry film resist having a small warpage and excellent flexibility and bendability.

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 from 10% to 100%, and even more preferably from 30% to 100%. Thereby, in the photosensitive dry film resist 3, high flame retardance, flexibility, and flexibility can be realized.

  In addition, a polyamide including at least 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 weight average molecular weight / number average molecular weight of the acid is preferably 2 to 10, and more preferably 2 to 5.

  When at least one of the first photosensitive layer and the second photosensitive layer, preferably the first photosensitive layer contains the above polyamic acid, it is excellent in flame retardancy, moisture resistance, electrical reliability, and low warpage. And the photosensitive dry film resist which has a low imidation temperature is realizable.

  Of course, the binder polymer includes a structural unit represented by the general formula (2), a structural unit represented by the general formula (3), and a structural unit represented by the general formula (4) in some cases. In addition to the polyamic acid containing at least, other polyamic acid may be contained as long as the performance of the resulting photosensitive dry film resist is not adversely affected.

  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. Also in this case, the structural unit represented by the above general formula (2), the structural unit represented by the above general formula (3), and the structural unit represented by the above general formula (4). The same effect as in the case of the copolymer can be obtained.

  The polyamic acid contained as the binder polymer in the first photosensitive layer and the second photosensitive layer of the photosensitive dry film resist 3 is preferably the above-described one, but the other polyamic acid is represented by the following general formula (4).

(Wherein R ⁶ represents a tetravalent organic group, and R ⁷ represents the following chemical formula group (5)

(In Chemical Formula a, m represents an integer of 1 to 20, n represents an integer of 0 to 10, and in Chemical Formula f, R ⁸ represents a hydrogen atom, a methyl group, an ethyl group, or a butyl group. .)
A, b, c, d, e, f, or g. )
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.)
The polyamic acid which consists of a structural unit represented by these is mentioned.

  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 a conventional photosensitive dry film resist is possible, and warpage is small and flexible. -A photosensitive dry film resist having excellent flexibility can be realized.

  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 to 10. Preferably, it is 2-5.

  At least one of the first photosensitive layer and the second photosensitive layer, preferably both, is a polyamic acid composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4). When it contains, the photosensitive dry film resist which is excellent in a flame retardance, moisture resistance, electrical reliability, and low curvature property, and has a low imidation temperature is realizable.

  In addition, 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.

  The polyamic acid used as the binder polymer in the second photosensitive layer is preferably the same as the polyamic acid used in the first photosensitive layer, but other polyamic acids may be used.

  In addition to the polyamic acid described above, examples of the polyamic acid that can be contained as a binder polymer in the second photosensitive layer include a polyamic acid composed of a structural unit represented by the general formula (3).

[Soluble polyimide having carboxyl group and / or hydroxyl group]
In the present specification, “soluble polyimide” is intended to be a polyimide that is soluble in an organic solvent. More specifically, what shows the solubility of 1.0 g or more, preferably 5.0 g or more, more preferably 10 g or more at 20 ° C. with respect to 100 g of the organic solvent is intended. If the solubility at 20 ° C. in 100 g of the organic solvent is less than 1.0 g, it tends to be difficult to form the photosensitive dry film resist 3 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 3 produced using the photosensitive resin composition described later tends to be sticky, and the cured film tends to be inferior in bending 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 3 is low. May decrease. 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 3 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.

(I-2-2) (Meth) acrylic compound The (meth) acrylic compound not only imparts good curability to the photosensitive dry film resist 3, but also the photosensitive dry film resist material 1. The viscoelasticity of the photosensitive dry film resist 3 at the time of heat processing can be lowered, and the fluidity at the time of heat lamination can be imparted. That is, heat lamination at a relatively low temperature is possible, and circuit irregularities can be embedded.

  The (meth) acrylic compound is 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 (meth) acrylic compound is not particularly limited, but a polyfunctional (meth) acrylic compound having at least two carbon-carbon double bonds is preferably included. According to such a (meth) acrylic compound, the crosslink density by light irradiation can be improved. Moreover, it is preferable that the compound which has at least 1 an aromatic ring and / or a heterocyclic ring is contained in 1 molecule. Thereby, heat resistance can be provided to the photosensitive dry film resist 3 obtained.

  Examples of (meth) acrylic compounds having at least one aromatic ring and / or heterocyclic ring and at least two carbon-carbon double bonds in one molecule include Aronix M-210 and M-211B (Toagosei Co., Ltd.). Bisphenol A EO modified di (meth) acrylate such as NK ester A-BPE-4, A-BPE-10-, A-BPE-30, bisphenol F EO modified such as Aronix M-208 (manufactured by Toagosei) (N = 2 to 20) Di (meth) acrylate, Denacol acrylate DA-250 (manufactured by Nagase Kasei Co., Ltd.) and other bisphenol A PO modified (n = 2 to 20) di (meth) acrylate and the like can be mentioned. It is not limited to these. 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, the hydrolysis resistance of the photosensitive dry film resist 3 obtained by using a (meth) acrylic compound containing at least one epoxy group and one or more (meth) acrylic groups in one molecule. And it becomes possible to improve the adhesiveness to copper 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 3 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- 320, Modification of phenol novolac epoxy acrylate such as NK Oligo EA-6340 (made by Shin-Nakamura Chemical), Karayad R-167, MAX-2104 (made by Nippon Kayaku), Denacol acrylate DA-212 (made 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) it can.

  By using polyester (meth) acrylate, flexibility can be imparted to the photosensitive dry film resist 3. 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 photosensitive dry film resist 3. 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, polyimide film, copper foil, etc.) to which the photosensitive dry film resist 3 is bonded 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, Lenglycol 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 Chryrate, 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 Recall diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2-bis [4- (acryloxy-diethoxy) phenyl] propane, 2,2-bis [4- (acryloxy-polyethoxy) 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, isos Allyl 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- (acryloxy polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy polypropoxy) phenyl] propane, 2, 4-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, allo Barbital, diallylamine, diallyldimethylsilane, diallyl disulfide, diallyl ether, zalyl sialate, diallyl isophthalate, diallyl terephthalate, 1,3-dialyloxy-2-propanol, diallyl sulfide diallyl maleate, 4,4'-isopropylidene diphenol 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-capri. Vinyl compounds such as rate; allyl compounds such as triallyl isocyanurate and diallyl phthalate may also be used.

  The first photosensitive layer and the second photosensitive layer may contain the (meth) acrylic compound as exemplified above alone or in combination of two or more. Further, the (meth) acrylic compound contained in the first photosensitive layer and the (meth) acrylic compound contained in the second photosensitive layer may be the same or different.

(I-2-3) Photoreaction initiator When the photosensitive dry film resist 3 is exposed, the photoreaction initiator promotes a crosslinking reaction or a polymerization reaction in the exposed region. Thus, the solubility of the photosensitive dry film resist 3 in the aqueous developer can be made sufficiently different between the exposed area and the unexposed area. Therefore, a pattern can be formed on the photosensitive dry film resist 3. It becomes possible to develop suitably.

  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 contained in the photosensitive dry film resist 3 as a photoreaction initiator is not particularly limited as long as it is a compound that generates radicals by light irradiation, but radicals can be generated by light irradiation at 250 nm to 450 nm. It is preferable that it is a compound which generate | occur | produces.

  Specifically, for example, the following general formulas (9) and (10)

(In the general formulas (9) and (10), 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 radical generated thereby can react with a reactive group having a double bond (vinyl, acryloyl, methacryloyl, allyl, etc.) to promote crosslinking.

  The acyl phosphine oxide represented by the general formula (9) generates two radicals, whereas the acyl phosphine oxide represented by the general formula (10) Generate radicals. Therefore, in this invention, it is more preferable to use the acyl phosphine oxide represented by the said General formula (10).

  Moreover, it is particularly preferable to use an oxime ester compound as the radical generator. The oxime ester compound has absorption in a long wavelength region, has a high photoreaction rate, and is not easily damaged by oxygen. Further, since the photobleaching occurs, the light easily penetrates and the thick film curing becomes relatively easy. By using the oxime compound, a photosensitive dry film resist with high sensitivity and high resolution can be obtained.

  Examples of oxime ester compounds include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (О-benzoyloxime)], and ethanone-1- [9-ethyl-6- (2-methylbenzoyl). -9H-carbazol-3-yl] -1- (0-acetyloxime) and the like.

  Examples of radical generators other than oxime esters include ketone compounds such as 2,2-dimethoxy-1,2-diphenylethane-1-one and 2-hydroxy-2-methyl-1-phenyl-propan-1-one. Phosphine oxide compounds such as bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (-2,4 There may be mentioned titanocene compounds such as -cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-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 diphenylanthraquinone sulfonic acid diphenyliodonium salt, 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.

  Furthermore, as the photobase generator, benzyl alcohol-urethane compound obtained by reaction of nitrobenzyl alcohol or dinitrobenzyl alcohol with isocyanate, nitro-1-phenylethyl alcohol, dinitro-1-phenylethyl alcohol and isocyanate And phenyl alcohol-urethane compound obtained by reaction with propanol-urethane compound, propanol-urethane compound obtained by reaction of dimethoxy-2-phenyl-2-propanol and isocyanate, and the like.

  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 contained in the photosensitive dry film resist 3. .

  Moreover, you may use for the photosensitive dry film resist 3 combining a peroxide and a sensitizer as said photoreaction initiator. According to such a configuration, the photosensitive dry film resist 3 can achieve practical photosensitivity.

  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. Among these, it is particularly preferable to use 2,4-diethylthioxanthone. In addition, the said sensitizer may be contained individually by 1 type and may be contained in combination of 2 or more types.

  In the embodiment in which the first photosensitive layer and / or the second photosensitive layer contains a photoreaction initiator and a sensitizer, the combination of the photoreaction initiator and the sensitizer is particularly an oxime ester compound, A combination with 2,4-diethylthioxanthone is preferred.

  Further, in the first photosensitive layer and the second photosensitive layer, the content of the sensitizer is not particularly limited as long as the sensitizing effect is obtained and the developing property is not adversely affected. Good. Specifically, in the first photosensitive layer, the amount is preferably 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. It is more preferable that Similarly, in the second photosensitive layer, it is preferably 0.01 to 50 parts by weight, and 0.1 to 20 parts by weight with respect to 100 parts by weight of the (A2) binder polymer. It is more preferable. In the first photosensitive layer and the second photosensitive layer, the content of the peroxide is not particularly limited, but specifically, 1 to 200 parts by weight with respect to 100 parts by weight of the sensitizer. It is preferably part by weight, more preferably 1 part by weight to 150 parts by weight.

  The said 1st photosensitive layer and the 2nd photosensitive layer may contain the said photoreaction initiator independently, and may contain it combining 2 or more types. 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. The photopolymerization aid is not particularly limited, and specific examples include 4-diethylaminoethyl benzoate, 4-dimethylaminoethyl benzoate, 4-diethylaminopropyl benzoate, 4-dimethylaminopropyl benzoate, 4 -Dimethylaminoisoamylbenzoate, N-phenylglycine, N-methyl-N-phenylglycine, N- (4-cyanophenyl) glycine, 4-dimethylaminobenzonitrile, ethylene glycol dithioglycolate, ethylene glycol di (3-mer Kabutopropionate), trimethylolpropane thioglycolate, trimethylolpropane tri (3-mercaptopropionate), pentaerythritol tetrathioglycolate, pentaerythritol tetra (3-mercap) Propionate), 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, -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-a Benzal) -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-azidocinnami) Den) -4-hydroxycyclohexanone, 2,6-di (p-azidocinnamylidene) -4-carboxycyclohexanone, 2,6-di (p-azidocinnamylidene) -4-cyclohexanone, 3,5-di (P-azidocinnamylidene) -N-methyl-4-piperidone, 4,4′-diazidochalcone, 3,3′-diazidochalcone, 3,4′-diazidochalcone, 4,3′-di Azido chalcone, 1,3-diphenyl-1,2,3-propanetrione-2- (o-acetyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (on-propyl) Carbonyl) 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-methoxy) Phenyl) -1,2,3-propanetrione-2- (o-ethoxycarbonyl) oxime, 1- (p-methoxyphenyl) -3- (p-nitrophenyl) -1,2,3-propanetrione-2 -(O-phenyloxycarbonyl) oxime and the like can be used. Moreover, trialkylamines, such as a triethylamine, a tributylamine, a triethanolamine, can be mentioned as another photoinitiator.

  These photopolymerization assistants may contain one kind of compound alone, or may contain two or more kinds of compounds in combination.

  In the first photosensitive layer and the second photosensitive layer, the content of the photopolymerization assistant is not particularly limited as long as the sensitizing effect is obtained and the developability is not adversely affected. Good. Specifically, in the first photosensitive layer, the amount is preferably 0.01 parts by weight to 50 parts by weight, and 0.1 parts by weight to 20 parts by weight with respect to 100 parts by weight of the (A1) binder polymer. More preferably. Similarly, in the second photosensitive layer, it is preferably 0.01 to 50 parts by weight, and 0.1 to 20 parts by weight with respect to 100 parts by weight of the (A2) binder polymer. It is more preferable.

(I-2-4) Phosphorus-based flame retardant In this specification, "flame retardant" means that a flammable substance is made difficult to burn by adding or reacting with a flammable substance such as plastic, wood, or fiber. It means a substance that works. The “phosphorous flame retardant” is a flame retardant containing phosphorus. The phosphorus content of the phosphorus flame retardant is preferably 5.0% by weight or more, and more preferably 7.0% by weight or more when the phosphorus flame retardant is 100. By using such a phosphorus flame retardant, flame retardancy can be effectively imparted.

  Specific examples of the phosphorus flame retardant include, for example, condensed phosphorus such as phosphazene, phosphine, phosphine oxide, phosphate ester (including condensed phosphate ester) having a phosphorus-nitrogen double bond, and phosphite ester. Examples include acid esters and phosphazene compound phosphorus flame retardants. The photosensitive dry film resist 3 according to the present embodiment preferably contains phosphazene, condensed phosphate ester, and the like from the viewpoint of compatibility with the binder polymer, the (meth) acrylic compound, and the photoreaction initiator. More specific examples of such phosphorus flame retardants include SPE-100 (manufactured by Otsuka Chemical), SPH-100 (manufactured by Otsuka Chemical), TPP (triphenyl phosphate) (manufactured by Daihachi Chemical), TCP (tri Cresyl phosphate (made by Daihachi Chemical), TXP (trixylenyl phosphate) (made by Daihachi Chemical), CDP (cresyl diphenyl phosphate) (made by Daihachi Chemical), PX-110 (cresyl 2,6-xyle) Nylphosphate) (made by Daihachi Chemical Co., Ltd.) and the like; CR-733S (resorcinol diphosphate) (made by Daihachi Chemical Co., Ltd.), CR-741 (made by Daihachi Chemical Co., Ltd.), CR-747 (made by Daihachi Chemical Co., Ltd.) Non-halogen-type condensed phosphate ester such as PX-200 (manufactured by Daihachi Chemical). These exemplified phosphorus-based flame retardants can be suitably used as the phosphorus-based flame retardants contained in the photosensitive dry film resist 3 because they can impart flame retardancy and have hydrolysis resistance. Moreover, these phosphorus flame retardants may be contained alone or in combination of two or more.

  The photosensitive dry film resist 3 may contain a flame retardant other than the phosphorus-based flame retardant. Examples of such a flame retardant include a silicone compound having a high aromatic ring content.

  In the embodiment in which the second photosensitive layer contains (D2) a phosphorus-based flame retardant, the (D1) phosphorus-based flame retardant of the first photosensitive layer and the (D2) phosphorus-based flame retardant of the second photosensitive layer are: They may be the same or different.

(I-2-5) Other components In the first photosensitive layer and the second photosensitive layer, as described above, the (A) binder polymer, (B) (meth) acrylic compound, and (C) photoreaction. In addition to the initiator and (D) flame retardant, (E) other components 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. In addition, these other components may be the same or different in the first photosensitive layer and the second photosensitive layer. Hereinafter, other components will be specifically described.

〔Epoxy resin〕
By using an epoxy resin, it is possible to improve the adhesion of the photosensitive dry film resist 3 to a copper foil, a polyimide film, or the like.

  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 above epoxy resins may be used alone or in combination of two or more. In the first photosensitive layer and the second photosensitive layer, the content of the epoxy resin is not particularly limited, but in both the first photosensitive layer and the second photosensitive layer, (A) 100 wt. Is preferably in the range of 1 to 100 parts by weight, more preferably in the range of 0 to 50 parts by weight, and in the range of 1 to 30 parts by weight. It is particularly preferred. In particular, when the amount is suppressed to 30 parts by weight or less, the bending resistance is not lowered.

[Curing accelerator and / or curing agent]
When an epoxy resin is contained as the first photosensitive layer and the second photosensitive layer, a curing accelerator and / or a curing agent is added to the first photosensitive layer and the second photosensitive layer in order to efficiently cure the photosensitive dry film resist 3. May be added. 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 content of the curing accelerator and / or curing agent is preferably in the range of 0.1 to 20 parts by weight, and 0.5 to 20 parts by weight with respect to 100 parts by weight of the (A) binder polymer. More preferably, it is in the range of 0.5 parts by weight to 15 parts by weight. When the content is 0.1 parts by weight or more, the epoxy resin can be sufficiently cured. Moreover, if it is 20 weight part or less, a heat resistant fall will not be caused.

[Polymerization inhibitor, stabilizer, antioxidant]
In the first photosensitive layer and the second photosensitive layer, photopolymerizable / thermopolymerizable such as vinyl group, acrylic group, methacrylic group, etc. contained in (A) binder polymer and / or (B) (meth) acrylic compound. In order to prevent a functional group from cross-linking during storage of the photosensitive resin composition and the photosensitive dry film resist material 1 for forming the first photosensitive layer and the second photosensitive layer, a polymerization inhibitor and a stabilizer It is preferable to add at least one polymer additive selected from the group consisting of antioxidants.

  The said polymerization inhibitor is not specifically limited, What is necessary is just what is generally used as a polymerization inhibitor and 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.

  The polymer additive selected from the group consisting of the above polymerization inhibitor, stabilizer and antioxidant is not particularly limited, and is generally a polymerization inhibitor, a polymerization inhibitor, a heat stabilizer, a light stabilizer, an oxidation agent. What is necessary is just to be used as an inhibitor and a radical scavenger. For example, hydroquinone, methylhydroquinone, 2,5-di-t-butylhydroquinone, t-butylhydroquinone, 2,5-bis (1,1,3,3-tetramethylbutyl) hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.) , Trade name DOHQ), 2,5-bis (1,1-dimethylbutyl) hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd., trade name DHHQ) and the like; p-benzoquinone, methyl-p-benzoquinone, t -Benzoquinone compounds such as butylbenzoquinone and 2,5-diphenyl-p-benzoquinone; pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (Ciba Specialty Chemicals ( Co., Ltd., trade name: Irganox 1010), N, N′-hexane-1,6-dii Bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide] (product 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), hydroxyphenol benzotriazole (Asahi Denka Kogyo ( Co., Ltd., trade name Adeka AO-20) and other hindered phenol compounds; 2- (2H-benzotriazol-2-yl) -p-; Cresol (Ciba Specialty Chemicals Co., Ltd., trade name) Benzotriazole compounds such as TINUVIN P); N-nitrosophenylhydroxylamine (manufactured by Wako Pure Chemical Industries, Ltd., trade name Q-1300), N-nitro Nitrosamine compounds such as phenylhydroxylamine aluminum salt (trade name Q-1301 manufactured by Wako Pure Chemical Industries, Ltd.); organic sulfur compounds such as phenothiazine, dithiobenzoyl sulfide, dibenzyltetrasulfide; bis (1,2,2, 6,6-pentamethyl-4-piperidyl) [{3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl} methyl] butyl malonate (manufactured by Ciba Specialty Chemicals, Hindered amine compounds such as trade name Irganox 144); aromatic amines such as p-phenylenediamine (commonly called paramine) and N, N-diphenyl-p-phenylenediamine; tris (2,4-di-t-butylphenyl) phos Fight (product name, Irganox 168) Tetrakis (2,4-di-t-bu Butylphenyl) [1,1-biphenyl] -4,4'-diyl bisphosphonate (manufactured by the same company, and a trade name Irganox P-EPQ) Phosphorus-based compounds such as.

  Particularly preferred are hydroquinone compounds, hindered phenol compounds, nitrosamine compounds, and aromatic amines. By using these compounds, the cross-linking reaction of the photopolymerizable / thermopolymerizable functional group can be prevented, so that during the storage of the photosensitive resin composition for forming the first photosensitive layer and the second photosensitive layer. The increase in the viscosity of the organic solvent solution of the photosensitive resin composition can be suppressed, and the storage stability of the photosensitive dry film resist material 1 can be improved. Furthermore, since it also has an antioxidant effect, it is possible to prevent deterioration of the resin and to improve the long-term heat resistance and hydrolysis resistance of the cured photosensitive dry film resist 3 produced from the photosensitive resin composition. .

  The amount of the polymerization inhibitor used is 0.00001 parts by weight 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). Preferably, it is in the range of 0.0001 parts by weight to 1 part by weight. If the usage-amount of the said photoreaction initiator and / or sensitizer is 0.00001 weight part or more, the stability at the time of storage will not fall. Moreover, if it is 5 parts weight or less, the sensitivity with respect to an active energy ray will not fall.

[Adhesion imparting agent]
In order to improve the adhesion between the photosensitive dry film resist 3 and a substrate such as a polyimide film or metal, a known so-called adhesion imparting agent may be added. The adhesion-imparting agent is preferably added to the second photosensitive layer serving as an adhesion surface with the substrate.

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

(I-3) Protective film As described above, a protective film may be laminated on the surface 5 of the photosensitive dry film resist 3. The material of the protective film is not particularly limited. Specifically, for example, a polyethylene film (PE film), a polyethylene vinyl alcohol film (EVA film), and a “copolymer film of polyethylene and ethylene vinyl alcohol” are used. (Hereinafter also referred to as “(PE + EVA) copolymer film”), “bonded body of PE film and (PE + EVA) copolymer film”, or “(PE + EVA) copolymer and polyethylene co-extrusion method” Film "(one side is a PE film side and the other side is a (PE + EVA) copolymer film side). Among the above-exemplified films, the PE film has an advantage that it is inexpensive and has excellent surface slipperiness. In addition, the (PE + EVA) copolymer film has appropriate adhesion to the photosensitive dry film resist 3 and peelability. Therefore, by using such a protective film, when the structural sheet laminated with the protective film, the photosensitive dry film resist, and the support film is rolled up, the surface slipperiness can be improved. it can. The protective film is not an essential component of the photosensitive dry film resist material 1.

  Since the photosensitive dry film resist material 1 has the above-described configuration, the second photosensitive layer is used by being laminated so as to be in contact with the side of the copper-clad laminate (also referred to as CCL with a circuit) on which the circuit is formed. The resolution, flame retardancy, moisture resistance, and electrical reliability of the photosensitive dry film resist 3 can be improved. This point will be described in more detail. In the above configuration, the concentration of the phosphorus-based flame retardant in the portion of the photosensitive dry film resist 3 that is in contact with the copper-clad laminate on which the circuit is formed (that is, the second photosensitive layer) is low. Therefore, it is possible to prevent a decrease in moisture resistance at a portion in contact with the copper-clad laminate. Therefore, it is considered that the electrical reliability can be effectively improved.

  In addition, the photosensitive dry film resist 3 exhibits photosensitivity when the photoreaction initiator generates radicals or the like by light irradiation and the (meth) acrylic compound is crosslinked. Here, when the density | concentration of a phosphorus flame retardant is high, the density | concentration of the generated radical etc. will be reduced, or the crosslinking density (concentration) of a (meth) acrylic-type compound will be reduced, and photosensitivity will fall. In particular, this tendency is large on the side far from the side irradiated with light (deep part). However, according to the said structure, the density | concentration of the phosphorus flame retardant of the 2nd photosensitive layer which is a side far from the light irradiation side, ie, the side which contact | connects a copper clad laminated board, is low. Therefore, resolution and photosensitivity can be improved. Furthermore, according to the said structure, the alkali solubility of a 2nd photosensitive layer improves. Therefore, a residue hardly occurs during alkali development, and the resolution and photosensitivity can be further improved.

<II. Method for producing photosensitive dry film resist material>
The method for producing a photosensitive dry film resist material according to the present invention (hereinafter also simply referred to as “the production method according to the present invention”) is a method for producing the above-described photosensitive dry film resist material according to the present invention. However, it goes without saying that the photosensitive dry film resist material of the present invention is not limited to those obtained by the production method described below.

  Specifically, the production method according to the present invention includes a step of producing a photosensitive resin composition for forming a photosensitive dry film resist (hereinafter also referred to as “photosensitive resin composition production step”), And a step of forming a photosensitive dry film resist on the support film using the photosensitive resin composition (hereinafter also referred to as “photosensitive dry film resist forming step”). Furthermore, a step of laminating a protective film on the photosensitive dry film resist (hereinafter also referred to as “protective film laminating step”) may be included. Hereinafter, the photosensitive resin composition manufacturing process, the photosensitive dry film resist forming process, and the protective film laminating process will be described in detail.

(II-1) Photosensitive resin composition manufacturing process In the photosensitive resin composition manufacturing process, a photosensitive resin composition used for forming a photosensitive dry film resist of the photosensitive dry film resist material according to the present invention is manufactured. To do.

  Here, <I. The configuration of the photosensitive dry film resist including the first photosensitive layer and the second photosensitive layer described in “Photosensitive dry film resist material> will be described, but the present invention is not limited thereto. That is, what is necessary is just to change suitably according to the structure and composition of the photosensitive dry film resist mentioned above.

  In this embodiment, in the photosensitive resin composition manufacturing process, (A1) binder polymer, (B1) (meth) acrylic compound, (C1) photoreaction initiator, and (D1) phosphorus flame retardant are essential components. A first photosensitive resin composition containing a desired ratio, and a second photosensitive resin composition containing (A2) a binder polymer and (B2) a (meth) acrylic compound as essential components in a desired ratio. To manufacture.

  The first photosensitive resin composition may contain (E1) other components as necessary. Moreover, it is preferable that the said 2nd photosensitive resin composition further contains (C2) photoreaction initiator. Moreover, you may contain another component (E2) as needed like the 1st photosensitive resin composition. Furthermore, although the said 2nd photosensitive resin composition may contain (D2) phosphorus flame retardant, it is preferable not to contain substantially.

  In the photosensitive resin composition production process, a binder polymer, a (meth) acrylic compound, a photoreaction initiator, a phosphorus flame retardant used in the production of the first photosensitive resin composition and the second photosensitive resin composition, For other ingredients, <I. What is illustrated to the photosensitive dry film resist material> may be used.

  Moreover, in the said photosensitive resin composition manufacturing process, the 1st photosensitive resin composition and the 2nd photosensitive resin composition are manufactured as a solution which melt | dissolved the said component uniformly in the organic solvent. Hereinafter, the first photosensitive resin composition and the second photosensitive resin composition may be referred to as an organic solvent solution of the first photosensitive layer and an organic solvent solution of the second photosensitive layer, respectively.

  The said organic solvent is not specifically limited, What is necessary is just an organic solvent which can melt | dissolve the component contained in a 1st photosensitive resin composition and a 2nd photosensitive 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 said organic solvent is removed in a subsequent process, the component contained in the said 1st photosensitive resin composition and the 2nd photosensitive resin composition is melt | dissolved, and a thing with a low boiling point as much as possible is selected. This is advantageous in the manufacturing process.

  The total weight of the (meth) acrylic compound contained in the first photosensitive resin composition and the second photosensitive resin composition is 1 to 400 parts by weight with respect to 100 parts by weight of the binder polymer (A). It is preferably in the range of parts by weight, more preferably in the range of 3 parts by weight to 300 parts by weight, still more preferably in the range of 1 part by weight to 200 parts by weight, and 1 part by weight to 100 parts by weight. It is particularly preferable that the amount be in the range of parts by weight. In addition, when a (meth) acrylic compound exceeding 200 parts by weight as the component (B) is added to 100 parts by weight of the binder polymer as the component (A), the resulting photosensitive dry film resist is not sticky. It tends to occur.

  Moreover, the total weight of the (C) photoreaction initiator contained in the first photosensitive resin composition and the second photosensitive resin composition is 0. 0 parts by weight with respect to 100 parts by weight of the binder polymer (A). It is preferably within the range of 01 parts by weight to 50 parts by weight. Moreover, it is preferable that it exists in the range of 0.001 weight part-10 weight part with respect to 100 weight part of total weight of the binder polymer which is (A) component, and the (meth) acrylic-type compound which is (B) component. More preferably, it is 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 can be configured to contain substantially no (C2) photoreaction initiator. In such an embodiment, the blending ratio of the (C2) photoreaction initiator in the second photosensitive resin composition is 0 part by weight to 0.01 part by weight with respect to 100 parts by weight of the (A2) binder polymer. The case where it is within the range is included. Furthermore, it may be in the range of 0 to 0.001 parts by weight with respect to 100 parts by weight of the total weight of the (A2) component binder polymer and the (B2) component (meth) acrylic compound. included.

  The said photosensitive resin composition manufacturing process may include the process (henceforth a "binder polymer synthesis process") which synthesize | combines the said binder polymer.

  Hereinafter, the binder polymer synthesis step will be described.

(II-1-1) Binder polymer synthesis step In the present invention, as described above, it is preferable to use a carboxyl group-containing vinyl polymer, a polyamic acid, and a soluble polyimide having a carboxyl group and / or a hydroxyl group as the binder polymer. . Therefore, here, the synthesis of a soluble polyimide having a carboxyl group-containing vinyl polymer, polyamic acid, carboxyl group and / or hydroxyl group will be described.

[Synthesis of carboxyl group-containing vinyl polymers]
The carboxyl group-containing vinyl polymer can be obtained by copolymerizing a carboxyl group-containing monomer and a monomer copolymerizable with the carboxyl group-containing monomer by a known method. As the carboxyl group-containing monomer and the monomer copolymerizable with the carboxyl group-containing monomer, <I. What is illustrated to the photosensitive dry film resist material> may be used.

(Synthesis of polyamic acid)
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.

  Specifically, for example, <I. In the case of synthesizing a polyamic acid composed of the structural unit represented by the above general formula (2) and the structural unit represented by the above general formula (3) exemplified in Photosensitive Dry Film Resist Material>, acid dianhydride And aromatic diamine, and the following general formula (6)

(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 synthesize | combine by making polysiloxane diamine represented by these react in an organic polar solvent.

  Further, for example, a polyamic acid comprising a structural unit represented by the general formula (2), a structural unit represented by the general formula (3), and a structural unit represented by the general formula (4) When synthesizing, acid dianhydride, aromatic diamine, polysiloxane diamine represented by the above general formula (6), and the following chemical formula group (7)

(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 synthesized by reacting a ′, b ′, c ′, d ′, e ′, f ′, or g ′ shown in FIG.

  For example, when synthesizing a polyamic acid composed of the structural unit represented by the general formula (3) and the structural unit represented by the general formula (4), an acid dianhydride and an aromatic diamine, It can synthesize | combine by making a ', b', c ', d', e ', f', or g 'shown by the said Chemical formula group (7) react in an organic polar solvent.

  In addition, when using a ', b', c ', d', e ', f', or g 'shown by the said Chemical formula group (7), these may be used independently and two or more types are used. You may use it in combination.

  For example, when synthesizing a polyamic acid composed of the structural unit represented by the general formula (4), it can be synthesized by reacting acid dianhydride and an aromatic diamine in an organic polar solvent. .

In the general formula (6), 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.

Moreover, in General formula (6), R < ³ > is a methyl group or a phenyl group each independently. 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 (6), 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 (6) 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 these acid dianhydrides is a suitable example of R < ¹ > in General formula (2), said R < ⁴ >, and R < ⁶ >. Specific examples of these acid dianhydrides 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 dianhydride, 2,2-bis (4-hydroxy) Phenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4 At least one of '-tetraphenylsilanetetracarboxylic dianhydride or 1,2-ethanedibenzoate-3,3', 4,4'-tetracarboxylic dianhydride is used 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.

  Moreover, although the said diamine is not specifically limited, It is preferable to use aromatic diamine. The aromatic diamine is not particularly limited. For example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 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'-trifluoro Romethylbenzanilide, 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) benzene, 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, 4,4′-bis [4- (4-amino-2-trifluoromethyl) phenoxy An aromatic diamine such as octafluorobiphenyl; an 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 diaminoresorcinol; 3,3'-diamino-4,4'-dihydroxybiphe Nil, 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′-dihydroxydiphenylate 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 4,4′-diamino-2,2′-dihydroxydiphenyl ether, 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxy Hydroxydiphenyl ether compounds such as diphenyl 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 and 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenylsulfone; 2,2-bis [4- (4-amino-3-hydroxyphenoxy) Bis [(hydroxyphenoxy) phenyl] al such as phenyl] propane Compounds; bis [(hydroxyphenoxy) phenyl] sulfone such as bis [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone and bis [4- (3-amino-4-hydroxyphenoxy) phenyl] sulfone Compounds; diaminophenols such as 2,4-diaminophenol; 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxydiphenylmethane, 4,4′- Bis such as diamino-2,2′-dihydroxydiphenylmethane, 2,2′-bis [3-amino-4-hydroxyphenyl] propane, 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl (Hydroxyphenoxy) biphenyl compounds; diaminophthalic acid such as 2,5-diaminoterephthalic acid 3,3′-diamino-4,4′-dicarboxybiphenyl, 4,4′-diamino-3,3′-dicarboxybiphenyl, 4,4′-diamino-2,2′-dicarboxybiphenyl, 4; Carboxybiphenyl compounds such as 3,4′-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 4,4 ′ Carboxydiphenylalkanes such as diamino-2,2 ′, 5,5′-tetracarboxydiphenylmethane; 3,3′-diamino-4,4′-dica Boxydiphenyl ether, 4,4′-diamino-3,3′-dicarboxydiphenyl ether, 4,4′-diamino-2,2′-dicarboxydiphenyl ether, 4,4′-diamino-2,2 ′, 5 Carboxydiphenyl ether compounds such as 5′-tetracarboxydiphenyl ether; 3,3′-diamino-4,4′-dicarboxydiphenyl sulfone, 4,4′-diamino-3,3′-dicarboxydiphenyl sulfone, 4,4 ′ Diphenylsulfone compounds such as -diamino-2,2'-dicarboxydiphenylsulfone and 4,4'-diamino-2,2 ', 5,5'-tetracarboxydiphenylsulfone; 2,2-bis [4- (4 Bis [(carboxyphene) such as -amino-3-carboxyphenoxy) phenyl] propane Noxy) phenyl] alkane compounds; bis [(carboxyphenoxy) phenyl] sulfone compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone; 3,5-diaminobenzoic acid and the like Of diaminobenzoic acid. These aromatic diamines can be used alone or in combination of two or more. Needless to say, in addition to the aromatic diamine, other known diamines may be used simultaneously as part of the raw material.

  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 (7) is reacted in an organic polar solvent is not particularly limited, and the acid dianhydride, The diamine and the polysiloxane diamine or the diamine of the above chemical formula group (7) may be reacted simultaneously, or the reaction between the acid dianhydride and the polysiloxane diamine or the diamine of the above chemical formula group (7) was started first. Thereafter, an aromatic diamine may be added and reacted, or after starting the reaction between the acid dianhydride and the aromatic diamine, polysiloxane diamine or the diamine of the above chemical formula group (7) is added and reacted. May be.

  In particular, it is more preferable to start the reaction between the acid dianhydride and the polysiloxane diamine or the diamine of the above chemical formula group (7) before adding an aromatic diamine to cause the reaction.

  In this case, first, an acid dianhydride and a polysiloxane diamine or a diamine of the above chemical formula group (7) may be reacted in an organic polar solvent, for example, from an acid dianhydride and an organic polar solvent. The polysiloxane diamine, the diamine of the above chemical formula group (7) or a solution thereof may be added to the resulting solution or suspension solution. Subsequently, the polyimide precursor (polyamic acid) used in the present invention can be synthesized by adding an aromatic diamine.

  Although it does not specifically limit as said organic polar solvent, It is advantageous on a process to select a thing which can melt | dissolve a polyamic acid and has a low boiling point as much as possible. Specifically, for example, formamide solvents such as dimethyl sulfoxide, N, N′-dimethylformamide, N, N′-diethylformamide; acetamides such as N, N′-dimethylacetamide and N, N′-diethylacetamide Solvents; pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone; hexamethylphosphoric triamide, dioxolane, tetrahydrofuran, 1,4-dioxane, acetonitrile and the like. 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 (7) is preferably performed in the organic polar solvent under a temperature condition of −20 ° C. to 80 ° C., It is more preferable to carry out the reaction under a temperature condition of −15 ° C. to 50 ° C. 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 (7) can be reacted. Moreover, it can prevent that the synthetic | combination polyamic acid decomposes | disassembles by setting it as 80 degrees C or less.

  In addition, the reaction time when the acid dianhydride is reacted with the polysiloxane diamine and / or the diamine of the above chemical formula group (7) is not particularly limited, and is, for example, 1 hour to 12 hours. Is preferred.

  In this case, 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 the above chemical formula group (7). 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 and reacted is preferably −20 ° C. to 80 ° C., more preferably −15 ° C. to 50 ° C. By setting it as the said temperature range, 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.

  The polyamic acid preferably has a logarithmic viscosity at 30 ° C. of a solution of 5 g / l N-methylpyrrolidone in the range of 0.2 to 4.0, preferably in the range of 0.3 to 2.0. Is more preferable.

  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. It is preferable to use aromatic dianhydride and aromatic diamine.

  Examples of the aromatic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenylsulfone. Tetracarboxylic dianhydride, 2,2-bis (hydroxyphenyl) propanedibenzoate-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-dio And the like aliphatic tetracarboxylic acid dianhydride having an aromatic ring and the like. The acid dianhydride may 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.

  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 acid dianhydride (polyamide acid synthesis reaction) is not particularly limited, but is preferably -20 ° C to 80 ° C, more preferably -15 ° C to 50 ° C. . 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.

[Soluble polyimide having carboxyl group and / or hydroxyl group]
The soluble polyimide having a carboxyl group and / or a hydroxyl group can be synthesized by first synthesizing a desired polyamic acid, dehydrating and ring-closing the polyamic acid, and imidizing. Here, it divides into the synthesis | combination of a polyamic acid and the imidation of a polyamic acid, and demonstrates in detail.

(A) Synthesis of Polyamic Acid Polyamic acid, which is a precursor of soluble polyimide having a carboxyl group and / or hydroxyl group, 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.

  The diamine is not particularly limited, but it is preferable to use a diamine having one or more carboxyl groups and / or hydroxyl groups in one molecule as at least a part from the viewpoint of aqueous developability. 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 (8)

(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 of 1 or more, n is an integer of 0 or more, and m and n are integers that satisfy the condition of m + n = 4, p is an integer of 1 or more, q is an integer of 0 or more, and p and 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 aromatic diamine represented by the above as a part of the raw material of the soluble polyimide.

  The aromatic diamine having a carboxyl group is not particularly limited. For example, diaminobenzoic acid such as 3,5-diaminobenzoic acid, 3,3′-diamino-4,4′-dicarboxybiphenyl, and the like. 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-carboxylic acid) Bis (carboxyphenoxy) biphenyl compounds such as phenoxy) phenyl] propane, bis [(carboxyphenoxy) phenyl] sulfone compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone, etc. It 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) hexafluoro Propane, bis (2-hydroxy-3-amino-5-methylphenyl) methane, 2,6-di [(2-hydroxy-3-amino-5-methylphenyl) methyl] -4-methylphenol, 2,6 Examples include compounds such as -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 part of the raw material, the acid equivalent of the resulting soluble polyimide containing a carboxyl group and / or a hydroxyl group 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. For example, bis [4- (3-aminophenoxy) phenyl] sulfone, [bis (4-amino-3-carboxy) phenyl] methane, the following general formula (1)

(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 polysiloxane diamine represented by these can be mentioned. 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.

  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 an acid dianhydride having two or more aromatic rings as at least a part of the raw material, and an acid diamine having four or more aromatic rings. More preferably, an anhydride is used as at least a part of the raw material.

  Examples of the acid dianhydride include aliphatic or alicyclic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, pyro 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, - dioxo-3-furanyl - naphtho and aliphatic tetracarboxylic dianhydride having an aromatic ring such as [1,2-c] furan-1,3-dione. The acid dianhydride may 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 Preferably, an acid dianhydride having two or more aromatic rings such as, 4,3 ′, 4′-tetracarboxylic dianhydride is used as at least a 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, 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 of the reaction between the diamine and acid dianhydride (polyamic acid synthesis reaction) is not particularly limited, but is preferably -20 ° C to 80 ° C, more preferably -15 ° C to 50 ° C. preferable. 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. 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.

(B) Imidization of polyamic acid Next, a method for imidizing the polyamic acid to obtain a soluble polyimide having a carboxyl group and / or a hydroxyl group using the polyamic acid will be described. 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 ° C. to 200 ° C. to positively generate water generated by dehydration ring closure. The reaction may be carried out for about 1 to 5 hours while being removed 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, after casting or applying a polyamic acid solution to a film-like support such as a glass plate, a metal plate, or PET (polyethylene terephthalate), 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. The soluble 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, it is generally 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 soluble 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 said soluble polyimide has a hydroxyl group, since the reaction of the acid anhydride added as a dehydrating agent and a hydroxyl group is considered, the acid anhydride to be used is stoichiometrically the minimum necessary for imidization. It is preferable to make this amount.

(II-2) Photosensitive dry film resist forming step In the photosensitive dry film resist forming step, a photosensitive dry film is formed on the support film by using the photosensitive resin composition manufactured in the photosensitive resin composition manufacturing step. A resist is formed. Examples of the support film include <I. What is illustrated by the photosensitive dry film resist material> may be used. Moreover, the method of forming a photosensitive dry film resist on this support film is not specifically limited, A conventionally well-known method can be used. Here, an embodiment in which a photosensitive dry film resist having a two-layer structure is formed using the first photosensitive resin composition and the second photosensitive resin composition will be described below. It is not limited. That is, a photosensitive dry film resist having any layer structure can be formed using the same principle (method) according to the layer structure of the photosensitive dry film resist.

  In this embodiment, after apply | coating said 1st photosensitive resin composition uniformly on a support film, heating and / or hot air spraying are performed. Thereby, the said organic solvent is removed and the 1st photosensitive resin composition in which the 1st photosensitive 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 first photosensitive resin composition is dried by performing the above heating and / or hot air blowing is curable such as (meth) acrylic group and epoxy group contained in the first photosensitive resin composition. Any temperature at which the group does not react may be used. 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.

  Subsequently, a second photosensitive layer is formed on the surface of the first photosensitive layer using the second photosensitive resin composition. The method for forming the second photosensitive layer on the surface of the first photosensitive layer is not particularly limited, and a conventionally known method may be used. Specifically, for example, 1) direct coating method and 2) transfer method can be mentioned. 1) In the direct coating method, the second photosensitive layer can be formed by applying and drying the second photosensitive resin composition on the surface of the first photosensitive layer. In addition, in the 2) transfer method, after the second photosensitive resin composition is applied to the surface and the solution coating surface of the dried protective film is bonded to the first photosensitive layer, the first photosensitive layer is peeled off by peeling off the protective film. The second photosensitive layer is transferred to the surface of the layer.

  In the case of the method 1), after the first photosensitive layer is formed on the support film, the second photosensitive resin composition is uniformly applied to the surface of the first photosensitive layer using an application tool such as a gravure mesh. Thereafter, the solvent is removed by heating and / or hot air blowing, and drying is performed. In this manner, a photosensitive dry film resist material 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.

  On the other hand, in the case of the above method 2), the second photosensitive 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 the solvent is removed by heating and / or hot air blowing. And dry. The first photosensitive layer was formed so that the protective film ("protective film / second photosensitive layer") on which the second photosensitive layer thus obtained was formed was bonded to the first photosensitive layer. It is bonded to a support film (“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, when the protective film is peeled off, a photosensitive dry film resist material having a structure of “support film / first photosensitive layer / second photosensitive layer” is obtained.

(II-3) Protective film laminating step In the protective film laminating step, a protective film is laminated on the photosensitive dry film resist formed in the photosensitive dry film resist forming step. The method for laminating the protective film is not particularly limited, and a conventionally known method can be used. Specifically, for example, a protective film can be laminated and laminated on a photosensitive dry film resist. In addition, the temperature at the time of a lamination process should just be a temperature by which the thermal expansion of a protective film does not occur and a wrinkle and a curl do not arise in the protective film after a lamination process. Specifically, the temperature during the laminating process is preferably 10 ° C to 50 ° C. Moreover, 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.

  The material of the protective film is not particularly limited, and <I. The protective film exemplified in Photosensitive dry film resist material> may be used.

<III. Printed wiring board>
The photosensitive dry film resist material concerning this invention can be used for the insulating protective layer of a printed wiring board. More specifically, the photosensitive dry film resist of the photosensitive dry film resist material according to the present invention can be used as an insulating protective layer of a printed wiring board. Therefore, the present invention also includes a printed wiring board using the photosensitive dry film resist of the photosensitive dry film resist material according to the present invention as an insulating protective layer.

  In the printed wiring board concerning this invention, the said photosensitive dry film resist material should just be laminated | stacked so that the said 2nd photosensitive layer may contact | connect the copper clad laminated board in which the circuit was formed. According to said structure, the printed wiring board excellent in the flame retardance, moisture resistance, and electrical reliability can be provided.

  The method for producing the printed wiring board according to the present invention will be specifically described below. Here, a photosensitive dry film resist material including a photosensitive dry film resist having a two-layer structure is used as an insulating protective layer, and a patterned circuit is formed as a printed wiring board (hereinafter also referred to as a CCL with a circuit). ) Is used as an example, but the present invention is not limited to this. That is, a photosensitive dry film resist material having a different structure from the photosensitive dry film resist can be used as the insulating protective layer. Similarly, also when forming a multilayer printed wiring board also about a printed wiring board, the photosensitive dry film resist material concerning this invention can be used as an interlayer insulation layer with the same method.

  First, when using the thing provided with a protective film as a photosensitive dry film resist material concerning this invention, a protective film is peeled first. Next, the CCL with a circuit is covered with a photosensitive dry film resist material so that the second photosensitive layer and the circuit portion of the CCL with a circuit face each other, and bonded together by thermocompression bonding. The bonding method by thermocompression bonding is not particularly limited, and may be performed by hot pressing, laminating (thermal laminating), hot roll laminating, or the like.

  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 capable of being crimped is preferably in the range of 50 ° C to 150 ° C, more preferably in the range of 60 ° C to 120 ° C, and in the range of 80 ° C to 120 ° C. It is particularly preferred.

  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.

  A photosensitive dry film resist material is laminated on the CCL with circuit by the above-described thermocompression treatment. 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 film has peeled after the exposure process, you may peel after bonding a photosensitive dry film resist material on CCL with a circuit, ie, before performing an exposure process. 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 nm 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 capable of dissolving 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% by weight to 10% by weight, but from the viewpoint of alkali resistance of the photosensitive dry film resist, 0.1% by weight. More preferably, it is within the range of 5% to 5% by weight.

  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 the developer onto the 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, but it is preferable that development is possible in a time of 180 seconds or less, and development is possible in a time of 90 seconds or less. 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 material 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 of the photosensitive dry film resist material is used as an insulating protective material or an interlayer insulating material of a printed wiring board has been described. It is.

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

  Although this invention is demonstrated more concretely based on an Example and a comparative example and FIGS. 1-5, this invention is not limited to this. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention. In the following Examples and Comparative Examples, the surface phosphorus content, the physical properties of the photosensitive dry film resist material, and the molecular weight of the polyamic acid were evaluated as follows.

[Analysis of surface phosphorus content]
First, a cross section of the photosensitive dry film resist material was cut into a section using an ultramicrotome / diamond knife. Then, the section was fixed on a carbon tape. Thus, about the section fixed on the carbon tape, using the scanning electron microscope-X-ray microanalyzer (Hitachi S-3000N HORIBA EMAX-7000), the second region of the photosensitive dry film resist (photosensitive dry film). Elemental analysis (measurement elements: P, C) of the first region (region from the support film side surface of the photosensitive dry film resist to a depth of 2 μm) from the surface opposite to the support film side of the film resist) ) (See FIG. 1). The analysis conditions for elemental analysis were an acceleration voltage of 15 kV and a measurement time of 100 seconds.

  Using the data thus obtained, the abundance ratio of phosphorus atoms in the first region and the second region (the detected intensity of P in the first region or the second region / the detected intensity of C) was calculated.

[Evaluation of physical properties of photosensitive dry film resist materials]
For photosensitive dry film resist materials, (i) alkali solubility, (ii) developability, (iii) resolution, (iv) adhesion, (v) flame retardancy, (vi) electrical reliability, (vii) solder Heat resistance, (viii) B-stage tackiness, and (iv) warpage were evaluated by the following methods.

(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. A photosensitive dry film resist material (after removing the protective film if a protective film is provided) was laminated on the glossy surface of the electrolytic copper foil (after soft etching) under the conditions of 100 ° C. and 75000 Pa · m. Next, after peeling off the PET film (support 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.) and a development time 30 Development processing was performed under the conditions of from 1 second to 180 seconds. 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% by weight of sodium carbonate aqueous solution (liquid temperature 40 ° C.) or 1% by weight of sodium carbonate aqueous 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. A photosensitive dry film resist material (after removing the protective film if a protective film is provided) was laminated on the glossy surface of the electrolytic copper foil (after soft etching) under the conditions of 100 ° C. and 75000 Pa · m. On the PET film (support film) of this laminate, a mask pattern depicting fine squares of 100 × 100 μm square and 200 × 200 μm square 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 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 material (after removing the protective film if a protective film is provided) was laminated on the glossy surface of the electrolytic copper foil. On the PET film (support film) of this laminate, a mask pattern in 10 μm increments from 40/40 μm to 200/200 μm in line / space 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 A photosensitive dry film resist material (after removing the protective film if a protective film is provided) is applied to a polyimide film having a thickness of 25 μm (NPI manufactured by Kaneka Corporation) at 100 ° C. and 75000 Pa · m. Laminated. Next, after exposing the light of wavelength 405nm only by 600mJ / cm < ² >, the support film was peeled off, and the heat curing was performed 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 Retardant A photosensitive dry film resist material (after removing the protective film if a protective film is provided) is placed on both sides of a 50 μm-thick polyimide film (NPI manufactured by Kaneka Corporation) at 100 ° C. and 75000 Pa. -Laminated with m. 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) 4 and 5 were used to form comb patterns with lines / spaces = 100/100 μm and 25/25 μm, respectively, to obtain CCL with circuit. A photosensitive dry film resist material (after removing the protective film if a protective film is provided) is layered so as to cover the comb-shaped pattern portion of the CCL with circuit, and the temperature is 100 ° C. and 75000 Pa · m. Laminated under conditions. 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 (product name: Platinums 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.

If the resistance value at the time of application time is 500 hours or more is 1.0 × 10 ⁸ Ω or more in at least line / space = 100/100 μm comb pattern, the circuit is passed, and the circuit is short-circuited in less than 500 hours. Those that would be 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 photosensitive dry film resist material cut into a 4 cm square (after removing the protective film if a protective film is provided) is placed on the glossy surface of the electrolytic copper foil (after soft etching), 100 ° C., Lamination was performed under conditions of 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) T-stage tackiness in the B-stage state The photosensitive dry film resist material (after removing the protective film if a protective film is provided) is examined for the presence or absence of tack by touching it. If it was acceptable and tackiness was strong, it was rejected.

(Iv) Warpage A photosensitive dry film resist material produced in the same manner as in the evaluation of adhesion (after removing the protective film if a protective film is provided) is aligned with polyimide film Apical 25 NPI (manufactured by Kaneka). Lamination was performed under the conditions of 20,000 Pa · m. Then, only 400 mJ / cm ^{2 of} 400 nm light was exposed, and then the PET film (support 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.

[Molecular weight of polyamic acid]
The molecular weight of the polyamic acid was measured using high-speed GPC (trade name HLC-8220GPC, manufactured by Tosoh Corporation). The measurement conditions were as follows: DMF (including 30 mM LiBr, 20 mM H ₃ PO ₄ ) was used as the eluent, TSK gel Super AWM-H (manufactured by Tosoh) was used as the column, column temperature was 40 ° C., and the detector was used. Polyethylene oxide and polyethylene glycol were used as standard samples at RI and a flow rate of 0.6 ml / min.

[Example 1: Production of photosensitive dry film resist material]
(1) Synthesis of polyamic acid In a 2000 ml separable flask equipped with a stirrer, 31.02 g (100 mmol) of ODPA and 102.7 g of dioxolane were taken, and 59.68 g (40 mmol: polysiloxane diamine X-22-9409S manufactured by Shin-Etsu Chemical Co., Ltd.). In general formula (6), R ² = propylene group, m was about 12, phenyl group content 25%, molecular weight 1492) was dissolved in dioxolane 59.68 g, 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.

  When the molecular weight of the obtained polyamic acid was measured, the weight average molecular weight was 160000, the number average molecular weight was 58000, and the weight average molecular weight / number average molecular weight was 2.75. Tg of polyamic acid polyimidated was 90 ° C.

(2) Preparation of 1st photosensitive resin composition and 2nd photosensitive resin composition The component shown below was mixed, dioxolane was added and it was made to melt | dissolve uniformly so that it may become solid content weight% (Sc) = 40%. The 1st photosensitive resin composition and the 2nd photosensitive resin composition (organic solvent solution) were prepared.
<First photosensitive resin composition>
(A1) Binder polymer • Polyamic acid synthesized in (1) above (converted as solid content): 100 parts by weight (B1) (meth) acrylic compound • Bisphenol A EO-modified di (meth) acrylate (Daicel) Cytec Co., Ltd., 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) 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, bisphenol A Bis (diphenyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., product name CR-741 15 parts by weight <second photosensitive resin composition
(A2) Binder polymer • Polyamic acid synthesized in (1) above (converted to solid content): 100 parts by weight (B2) (meth) acrylic compound • Bisphenol A EO-modified di (meth) acrylate (Hitachi Kasei Kogyo Co., Ltd., product name FA321M) 40 parts by weight (C2) Photoreaction initiator, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals Co., Ltd.) Irgacure 819) ... 1 part by weight.

(3) Production of photosensitive dry film resist material The first photosensitive resin composition is applied on East Lerminer T60 (25 μm thickness), dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes, and 12.5 μm. A thick coating film (first photosensitive layer) was prepared. Next, the second photosensitive resin composition was applied onto the coating film, and dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes to prepare a coating film (second photosensitive layer) having a thickness of 12.5 μm. That is, the thickness of the first photosensitive layer and the thickness of the second photosensitive layer were combined to be 25 μm.

  With respect to the photosensitive dry film resist material thus obtained, the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer and the second region including the second photosensitive layer was analyzed by the above method. The result of elemental analysis of the first region is shown in FIG. 2, and the result of elemental analysis of the second region is shown in FIG. Based on the data shown in FIGS. 2 and 3, the abundance ratio of phosphorus atoms in the first region and the second region was calculated. As a result, the abundance ratio of phosphorus atoms in the second region including the second photosensitive layer (region from the surface opposite to the support film of the photosensitive dry film resist to a depth of 2 μm) = 5 cps ÷ 93 cps = 0.0537. On the other hand, the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer (region from the surface of the photosensitive dry film resist on the support film side to a depth of 2 μm) = 11 cps ÷ 93 cps = 0.11827.

  In addition, the abundance ratio of phosphorus atoms in the second region including the second photosensitive layer / the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer was 0.45. That is, the abundance ratio of phosphorus atoms in the second region was 45% of the abundance ratio of phosphorus atoms in the first region.

(4) Evaluation of physical property of photosensitive dry film resist material About the obtained photosensitive dry film resist material, the physical property was evaluated using the above-mentioned evaluation method. The results are shown below.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Resolution: 70 μm.
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / space = 100/100 μm: 6.0 × 10 ¹¹ Ω, Line / space = 25/25 μm: 5.5 × 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 2: Production of photosensitive dry film resist material]
Using the same thing as Example 1 as a 1st photosensitive resin composition and a 2nd photosensitive resin composition, the photosensitive dry film resist material was manufactured with the following method.

  The first photosensitive resin composition is coated on East Lerminer T60 (25 μm thickness) and dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes to produce a coating film (first photosensitive layer) having a thickness of 12.5 μm. did. Next, the second photosensitive resin composition was applied on a PPS film (Torayna # 3000 manufactured by Toray Industries, Inc., thickness 25 μm) (protective film) so that the thickness after drying was 12.5 μm, and 60 ° C. For 2 minutes and at 100 ° C. for 10 minutes to remove the organic solvent.

  The roll film is 45 ° C. and the nip pressure is 50000 Pa · m so that the second photosensitive layer side is in contact with the surface of the first photosensitive layer produced as described above. Lamination was performed under the following conditions. The PPS film (protective film) was peeled off to obtain a photosensitive dry film resist material in which a first photosensitive layer and a second photosensitive layer were formed on a PET film (support film).

  About the photosensitive dry film resist material obtained in this way, the abundance ratio in the first region including the first photosensitive layer and the second region including the second photosensitive layer was analyzed by the above method. As a result, the phosphorus atom abundance ratio in the second region including the second photosensitive layer (region from the surface opposite to the photosensitive dry film resist support film to a depth of 2 μm) = 2.5 cps ÷ 93 cps = 0.0269. It was. On the other hand, the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer (region from the surface of the photosensitive dry film resist on the support film side to a depth of 2 μm) = 11 cps ÷ 93 cps = 0.11827.

  In addition, the abundance ratio of phosphorus atoms in the second region including the second photosensitive layer / the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer was 0.23. That is, the abundance ratio of phosphorus atoms in the second region was 23% of the abundance ratio of phosphorus atoms in the first region.

Next, physical properties of the obtained photosensitive dry film resist material were evaluated using the above-described evaluation method. The results are shown below.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Resolution: 70 μm.
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / space = 100/100 μm: 9.0 × 10 ¹¹ Ω, Line / space = 25/25 μm: 7.5 × 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 3: Production of photosensitive dry film resist material]
The following components are mixed, dioxolane is added and uniformly dissolved so that the solid content weight% (Sc) = 40%, and the first photosensitive resin composition, the second photosensitive resin composition, and the third photosensitive resin are mixed. Resin composition (organic solvent solution) was prepared.
<First photosensitive resin composition>
(A1) Binder polymer • Polyamic acid synthesized in 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 manufactured by Co., Ltd. 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 / phosphazene compound ( Otsuka Chemical Co., Ltd. product name SPH-100 ... 20 parts by weight <second photosensitive resin composition>
(A2) Binder polymer • Polyamic acid synthesized in Example 1 (converted to 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 (D2) Flame retardant / phosphazene compound (Otsuka Chemical Co., Ltd., product name SPH-100 ... 3 parts by weight <third photosensitive resin composition>
(A3) Binder polymer • Polyamic acid synthesized in Example 1 (converted in terms of solid content): 100 parts by weight (B3) (meth) acrylic compound • Bisphenol A EO-modified di (meth) acrylate (Hitachi Chemical) Industrial Co., Ltd., product name FA321M) 40 parts by weight (C3) Photoinitiator Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemicals Co., Ltd.) Irgacure 819) ... 1 part by weight (D3) Flame retardant / phosphazene compound (Otsuka Chemical Co., Ltd., product name SPH-100 ... 10 parts by weight.

  Next, the first photosensitive resin composition is applied onto East Lerminer T60 (25 μm thickness), dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes, and then a 10 μm thick coating film (first photosensitive layer) ) Was produced. Subsequently, the 3rd photosensitive resin composition was apply | coated on the coating film, and it dried at 60 degreeC for 2 minutes and 100 degreeC for 10 minutes, and produced the coating film (3rd photosensitive layer) of thickness 5 micrometers. Further, the second photosensitive resin composition was applied and dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes to prepare a coating film (second photosensitive layer) having a thickness of 10 μm. That is, the total thickness of the first photosensitive layer, the second photosensitive layer, and the third photosensitive layer was set to 25 μm.

  With respect to the photosensitive dry film resist material thus obtained, the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer and the second region including the second photosensitive layer was analyzed by the above method. As a result, the abundance ratio of phosphorus atoms in the second region including the second photosensitive layer (region from the surface opposite to the support film of the photosensitive dry film resist to a depth of 2 μm) = 6 cps ÷ 93 cps = 0.0645. On the other hand, the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer (region from the surface of the photosensitive dry film resist on the support film side to a depth of 2 μm) = 15 cps ÷ 93 cps = 0.1613.

  Further, the abundance ratio of phosphorus atoms in the second region including the second photosensitive layer / the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer was 0.40. That is, the abundance ratio of phosphorus atoms in the second region was 40% of the abundance ratio of phosphorus atoms in the first region.

Next, physical properties of the obtained photosensitive dry film resist material were evaluated using the above-described evaluation method. The results are shown below.
Developability: Both 100 μm × 100 μm square holes and 200 μm × 200 μm square holes were developed with no residue and passed.
Alkali solubility: Dissolved in 1% by weight sodium carbonate aqueous solution in 30 seconds.
Resolution: 70 μm.
Adhesion: Pass.
Flame resistance: Passed.
Electrical reliability: Passed. (Line / Space = 100/100 μm: 1.0 × 10 ¹¹ Ω, Line / Space = 25/25 μm: 1.3 × 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.

[Comparative Example 1]
(1) Synthesis of polyamic acid A 3 L separable flask was equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen introducing tank, and 87.3 g (400 mmol) of pyromellitic dianhydride and 496 g of N-methylpyrrolidone in a nitrogen atmosphere. Was put into the flask, and the internal temperature was raised to 50 ° C. while stirring the flask. At that temperature, polysiloxane diamine BY16-853U manufactured by Toray Dow Corning Silicone Co., Ltd. (R ² = propylene group, m is about 10, and phenyl group content is 0% in general formula (6)) 92. 6 g (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, followed by stirring in a nitrogen atmosphere for 20 hours to obtain polyamic acid. The weight average molecular weight of this polyamic acid was 120,000.

(2) Preparation of first photosensitive resin composition The following components are mixed, and dioxolane is added and dissolved uniformly so that the solid content wt% (Sc) = 40%. Manufactured.
<First photosensitive resin composition>
(A1) Binder polymer • Polyamic acid synthesized in (1) above (converted to solid content): 100 parts by weight (B1) (meth) acrylic compound • Pentaerystol acrylate (manufactured by Toa Gosei 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) Hikari Reaction initiator, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by Ciba Specialty Chemicals Co., Ltd.) 2 parts by weight (D1) Flame retardant, bisphenol A bis (diphenyl) ) Phosphate (manufactured by Daihachi Chemical Co., Ltd., product name CR-741...

(3) Production of photosensitive dry film resist material The first photosensitive resin composition is applied on East Lerminer T60 (25 μm thickness), dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes, and has a thickness of 25 μm. A coating film (first photosensitive layer) was prepared. In this way, a photosensitive dry film resist material in a B-stage state without the second photosensitive layer was produced.

  About the photosensitive dry film resist material obtained in this way, the first region (region from the support film side surface of the photosensitive dry film resist to a depth of 2 μm) and the second region (support film of the photosensitive dry film resist) The abundance ratio of phosphorus atoms in the region from the opposite surface to a depth of 2 μm was analyzed by the above method. As a result, the abundance ratio of phosphorus atoms in the second region (region from the surface opposite to the support film of the photosensitive dry film resist to a depth of 2 μm) = 14.5 cps ÷ 93 cps = 0.1559. On the other hand, the abundance ratio of phosphorus atoms in the first region (region from the surface of the photosensitive dry film resist on the support film side to a depth of 2 μm) = 14.5 cps ÷ 93 cps = 0.159.

  Moreover, the abundance ratio of phosphorus atoms in the second region / the abundance ratio of phosphorus atoms in the first region was 1.0. That is, the abundance ratio of phosphorus atoms in the second region was equal to the abundance ratio of phosphorus atoms in the first region.

(4) Evaluation of physical property of photosensitive dry film resist material About the obtained photosensitive dry film resist material, the physical property was evaluated using the above-mentioned evaluation method. The results are shown below.
Alkali solubility: Dissolved in an aqueous solution of 1% by weight sodium carbonate in 60 seconds.
Developability: A 100 μm × 100 μm square hole cannot be developed, but a 200 μm × 200 μm square hole 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 having the same abundance ratio of phosphorus atoms in the first region and the second region of the photosensitive dry film resist is inferior in developability, resolution, and electrical reliability, and has a B-stage state tack. As a result, the handling property was also poor.

[Comparative Example 2]
The following components were mixed, and dioxolane was added and dissolved uniformly so that the solid content weight% (Sc) = 40%, thereby producing a first photosensitive resin composition and a second photosensitive resin composition. .
<First photosensitive resin composition>
(A1) Binder polymer-Polyamic acid synthesized in Comparative Example 1 (converted to solid content) ... 100 parts by weight (B1) (Meth) acrylic compound-Pentaerystol 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 <second photosensitive resin composition>
(A2) Binder polymer-Polyamic acid synthesized in Comparative Example 1 (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 · Bisphenol A bis (diphenyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., product name CR-741 ··· 30 parts by weight.

  Next, the first photosensitive resin composition is applied onto East Lerminer T60 (25 μm thickness), dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes, and a 20 μm thick coating film (first photosensitive layer) ) Was produced. Next, the second photosensitive resin composition was applied onto the coating film, and dried at 60 ° C. for 2 minutes and at 100 ° C. for 10 minutes to prepare a coating film (second photosensitive layer) having a thickness of 5 μm. Thus, a photosensitive dry film resist material in a B stage state in which the thickness of the first photosensitive layer was 20 μm and the thickness of the second photosensitive layer was 5 μm was manufactured. That is, the total thickness of the first photosensitive layer and the second photosensitive layer was set to 25 μm.

  With respect to the photosensitive dry film resist material thus obtained, the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer and the second region including the second photosensitive layer was analyzed by the above method. As a result, the abundance ratio of phosphorus atoms in the second region including the second photosensitive layer (region from the surface opposite to the support film of the photosensitive dry film resist to a depth of 2 μm) = 16.5 cps ÷ 93 cps = 0.1774. It was. On the other hand, the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer (region from the support film side surface of the photosensitive dry film resist to a depth of 2 μm) = 4.5 cps ÷ 93 cps = 0.0484.

  Further, the abundance ratio of phosphorus atoms in the second region including the second photosensitive layer / the abundance ratio of phosphorus atoms in the first region including the first photosensitive layer was 3.67. That is, the abundance ratio of phosphorus atoms in the second region was 367% of the abundance ratio of phosphorus atoms in the first region.

Next, physical properties of the obtained photosensitive dry film resist material were evaluated using the above-described evaluation method. The results are shown below.
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:-(not developable).
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.

  Thus, in the photosensitive dry film resist which does not contain a flame retardant in the first region of the photosensitive dry film resist and contains the flame retardant in the second region, the developability, resolution, flame retardancy, and electrical reliability are improved. The result was inferior.

  The structures of the photosensitive dry film resists in Examples 1 to 3 and Comparative Examples 1 and 2 are summarized in Table 1, and the results of the physical property evaluation of the photosensitive dry film resists are summarized in Table 2.

  Note that the present invention is not limited to the configurations described above, and various modifications are possible within the scope of the claims, and technical means disclosed in different embodiments and examples respectively. Embodiments and examples obtained by appropriately combining them are also included in the technical scope of the present invention.

  As described above, in the present invention, in the photosensitive dry film resist material in which the photosensitive dry film resist is provided on the support film, the presence of phosphorus atoms on the first surface of the photosensitive dry film resist in contact with the support film. The abundance ratio of phosphorus atoms on the second surface located behind the first surface is made smaller than the ratio. Therefore, it is possible to obtain a photosensitive dry film resist material that has good aqueous developability and is excellent in flame retardancy, adhesion, moisture resistance, and electrical reliability. Therefore, this invention can be utilized in the field | area which manufactures the various resin molded products represented by the photosensitive dry film resist and the laminated body. Furthermore, it can be suitably used not only in the industry for manufacturing printed wiring boards such as FPC, for example, the resin industry for manufacturing resin materials for electronic components, but also in the industrial field of electronic equipment using such printed wiring boards. Can be widely applied.

Claims (8)

A photosensitive dry film resist material comprising a support film and a photosensitive dry film resist,
The photosensitive dry film resist is disposed on the support film,
The photosensitive dry film resist has a first surface in contact with the support film, and a second surface located on the back side of the first surface,
Abundance ratio of phosphorus atoms in the second surface, rather smaller than the presence ratio of phosphorus atoms in the first surface,
In the photosensitive dry film resist, the abundance ratio of phosphorus atoms in the second region from the second surface to a depth of 2 μm is smaller than the abundance ratio of phosphorus atoms in the first region from the first surface to a depth of 2 μm,
The abundance ratio of phosphorus atoms in the second region is 70% or less of the abundance ratio of phosphorus atoms in the first region,
The abundance ratio of phosphorus atoms in the first region is 0.05 to 0.4,
A photosensitive dry film resist material , wherein the abundance ratio of phosphorus atoms in the second region is 0 to 0.08 :
However, a. Comprising a top layer binder having a phosphorus portion and a top layer photoinitiator having a phosphorus portion and having a thickness of 1 to 75 microns; i. Phosphorus in the range of 2 weight percent to 10 weight percent; ii. A photoinitiator in the range of 2 weight percent to 18 weight percent, and iii. A top layer comprising a top layer binder in an amount of 20 weight percent to 70 weight percent;
b. Optionally comprising a bottom layer binder having a phosphorus moiety, and optionally a bottom layer photoinitiator having at least one phosphorus moiety, comprising phosphorus in an amount of 4 weight percent or less, from 1 micron to 75 microns And a bottom layer having a thickness of
And a photosensitive multilayer circuit coverlay composition characterized in that the total thickness is in the range of 2 microns to 150 microns . The photosensitive dry film resist material according to claim 1 , wherein a concentration gradient of phosphorus atoms is formed between the first surface and the second surface of the photosensitive dry film resist. The photosensitive dry film resist material according to claim 1 , wherein a protective film is further provided on the photosensitive dry film resist. The photosensitive dry film resist has a multilayer structure including at least a first photosensitive layer including the first surface and a second photosensitive layer including the second surface,
The first photosensitive layer contains (A1) a binder polymer, (B1) (meth) acrylic compound, (C1) a photoreaction initiator, and (D1) a phosphorus flame retardant as essential components.
The second photosensitive layer contains (A2) a binder polymer, and (B2) a (meth) acrylic compound as essential components,
The photosensitive dry film resist material according to claim 1 , wherein the second photosensitive layer does not substantially contain (D2) a phosphorus-based flame retardant. The photosensitive dry film resist material according to claim 4 , wherein the thickness of the first photosensitive layer is 1/5 or more of the thickness of the second photosensitive layer. A printed wiring board using the photosensitive dry film resist of the photosensitive dry film resist material according to any one of claims 1 to 5 as an insulating protective layer. The printed wiring board according to claim 6 , wherein the second surface and the circuit surface are in contact with each other. A printed wiring board, wherein the photosensitive dry film resist of the photosensitive dry film resist material according to any one of claims 1 to 5 is cured at a temperature of 180 ° C or lower and used as an insulating protective layer. Production method.

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