JP2007233319A - Photosensitive resin composition and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which can be subjected to imidation at a lower temperature as compared with the conventional composition, ensures small warpage and excellent flexibility/bendability/electric reliability/photosensitivity in a state it is laminated as a photosensitive dry film resist on an FPC substrate or the like, and has flame retardancy. <P>SOLUTION: The photosensitive resin composition contains at least (A) a polyimide precursor, (B) a (meth)acrylate compound having a carbon-carbon double bond and (C) a photoreaction initiator and cures at ≤180°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition and use thereof, and in particular, contains a polyimide precursor, a (meth) acrylate compound having a carbon-carbon double bond, and a photoinitiator as constituent components. The present invention relates to a photosensitive resin composition that can be cured at a temperature of 180 ° C. or lower and use thereof.

  In recent years, electronic devices have been rapidly increasing in functionality, performance, and size. Accordingly, electronic components are required to be reduced in size and weight. For this reason, the demand for flexible printed circuit boards (hereinafter also referred to as “FPCs”) is rapidly increasing in wiring boards for mounting electronic components as compared to conventional rigid printed wiring boards. It is increasing.

  In FPC, a polymer film called a coverlay film is bonded to the surface for the purpose of protecting the conductor surface. Conventionally, epoxy and acrylic adhesives have been mainly used for bonding the FPC and the coverlay film. However, the methods using these adhesives have problems such as (1) low heat resistance such as solder heat resistance and adhesive strength at high temperature, and (2) poor flexibility, and are used as coverlay films. The performance of the polymer film was not fully utilized.

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

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

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

  Until now, as a photosensitive polyimide, those having various compositions have been studied mainly for the purpose of use in semiconductors, and a polyamic acid (polyimide precursor) has a tertiary amine and a (meth) acryloyl group. An ion-bonded photosensitive polyimide mixed with a compound to form a photosensitive polyimide (see, for example, Patent Document 1), an ester-bonded photosensitive polyimide in which a methacryloyl group is introduced into the carboxyl group of a polyamic acid via an ester bond (See, for example, Patent Documents 2 and 3, etc.), photosensitive polyimide (see, for example, Patent Documents 4, 5, 6, 7, etc.) in which an isocyanate compound having a methacryloyl group is introduced into a carboxyl group portion of a polyamic acid (polyimide precursor) ), A photosensitive polyimide mixed with a polyamic acid and a (meth) acrylic compound (for example, Patent Document 8, 9, 10, 11, etc. reference.) And the like have been reported.

Among these, a photosensitive polyimide (see Patent Documents 8, 9, 10, 11, etc.) in which a polyamic acid and a (meth) acrylic compound are mixed is a photosensitive resin for producing a dry film for an FPC coverlay material. It has been reported to be used as a composition. In these Patent Documents 8 to 11, by using a photosensitive polyimide in which a polyamic acid and a (meth) acrylic compound are mixed, it is possible to develop with an alkaline aqueous solution that is more preferable than an organic solvent from the viewpoint of work safety, and a film after exposure. It has been reported that it is fully cured and exhibits high extensibility.
JP 54-145794 A (published November 14, 1979) Japanese Patent Publication No.55-030207 (released on August 9, 1980) Japanese Patent Publication No. 55-041422 (released on October 24, 1980) JP 59-160140 (published September 10, 1984) JP 03-170547 A (published July 24, 1991) Published in Japanese Patent Laid-Open No. 03-186847 (August 14, 1991) JP 61-118424 A (published June 5, 1986) 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)

  However, none of the conventional FPC photosensitive dry film resists described above have sufficient performance, such as low imidization temperature, low warpage, flame retardancy, excellent electrical reliability, flexibility, There is not yet anything that satisfies all of the flexibility and photosensitivity.

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

  None of the FPC photosensitive dry film resists obtained from conventional photosensitive resin compositions have sufficient performance, and can be imidized at a low temperature, and are laminated on the FPC as a photosensitive dry film resist. There was no photosensitive resin composition having small warpage, excellent flexibility, flexibility, electrical reliability, and photosensitivity and having flame retardancy.

  The present invention has been made in view of the above-described problems, and the object thereof is lower than that of the conventional one so that it can be applied to electronic parts having low heat resistance such as rigid and FPC boards. A photosensitive resin that can be imidized and has low warpage, flexibility, flexibility, electrical reliability, photosensitivity, and flame retardancy when laminated on a rigid or FPC substrate as a photosensitive dry film resist It is to provide a composition.

In order to solve the above problems, the photosensitive resin composition according to the present invention comprises at least (A) a polyimide precursor (B) a (meth) acrylate compound (C) photoreaction initiator having a carbon-carbon double bond. It is a photosensitive resin composition characterized by containing and curing at a temperature of 180 ° C. or lower.

Moreover, the photosensitive resin composition concerning this invention contains the (meth) acrylate compound (C) photoinitiator which has at least (A) polyimide precursor (B) carbon-carbon double bond, and is 160 degrees C or less. The photosensitive resin composition is characterized in that the polyimide precursor (A) is cured at the temperature of

  Moreover, in the photosensitive resin composition concerning this invention, the polyimide precursor does not contain 10 mol% or more of aromatic diamine containing a para bond in all diamines, and Tg after polyimide-izing is 200 degrees C or less. It is said.

 Moreover, in the photosensitive resin composition concerning this invention, in addition to (A)-(C) component, it contains the flame retardant as (D) component.

 Moreover, in the photosensitive resin composition concerning this invention, a polyimide precursor is the following general formula (1).

（式中、Ｒ¹は４価の有機基を示し、Ｒ²はメタ位で直接結合している芳香族化合物を示す。）で表される構成単位と一般式（２）

(Wherein R ¹ represents a tetravalent organic group and R ² represents an aromatic compound directly bonded at the meta position) and the general formula (2)

（式中、Ｒ¹は４価の有機基を示し、Ｒ³は一般式（３）か一般式（４）を示し、ただし、一般式（３）のＲ⁴は、−（ＣＨ₂）_n−であり、Ｒ⁵はメチル基かフェニル基であり、Ｒ⁵中のフェニル基の含有率が１５〜４０％でありｍは４〜２０の数で、ｎは２〜５の整数で
ある。また、一般式（４）中Ｒ⁶はＨ，メチル基，エチル基，ブチル基を、ｒは１〜２０の整数を、ｓは０〜１０の整数を示す。）で表される構成単位を含むことを特徴としている。

(In the formula, R ¹ represents a tetravalent organic group, R ³ represents the general formula (3) or the general formula (4), provided that R ^{4 in the} general formula (3) represents — (CH ₂ ) _n. R ⁵ is a methyl group or a phenyl group, the phenyl group content in R ⁵ is 15 to 40%, m is a number of 4 to 20, and n is an integer of 2 to 5. In the general formula (4), R ⁶ represents H, a methyl group, an ethyl group, or a butyl group, r represents an integer of 1 to 20, and s represents an integer of 0 to 10). It is characterized by including.

また、本発明にかかる感光性樹脂組成物において、前記一般式（１）中Ｒ²のメタ位で直接結合している芳香族化合物が、ｍ−フェニレンジアミン、３，３’−ジアミノジフェニルメタン、３，３’−ジアミノフェニルエーテル、３，３’−ジアミノフェニルスルフィド、３，３’−ジアミノフェニルスルフォン、３，３’−ジアミノベンズアニリド、２，２−ビス（３−アミノフェニル）ヘキサフルオロプロパン、２，２−ビス［４−（３−アミノフェノキシ）フェニル］プロパン、２，２−ビス［４−（３−アミノフェノキシ）フェニル］スルフォン、２，２−ビス［４−（３−アミノフェノキシ）フェニル］ヘキサフルオロプロパン、１，４−ビス（３−アミノフェノキシ）ベンゼン、４，４’−ビス（３−アミノフェノキシ）−ビフェニル、ン、１，３−ビス（３−アミノフェノキシ）ベンゼン、ビス［４−（３−アミノフェノキシ）フェニル］スルフォン、２，２−ビス（３−アミノフェニル）プロパンからなる群より選ばれる少なくとも１種の化合物のアミノ基を除いた構造であることを特徴としている。

In the photosensitive resin composition according to the present invention, the aromatic compound directly bonded at the meta position of R ^{2 in} the general formula (1) is m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3 , 3′-diaminophenyl ether, 3,3′-diaminophenyl sulfide, 3,3′-diaminophenyl sulfone, 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, At least one selected from the group consisting of 1,3-bis (3-aminophenoxy) benzene, bis [4- (3-aminophenoxy) phenyl] sulfone, and 2,2-bis (3-aminophenyl) propane It is characterized by the structure excluding the amino group of the compound.

  Moreover, the photosensitive dry film resist concerning this invention is obtained from the said photosensitive resin composition, It is characterized by the above-mentioned.

  A printed wiring board according to the present invention is characterized in that the photosensitive dry film resist is formed as an insulating protective layer.

  A printed wiring board according to the present invention is characterized by a method for producing a printed wiring board, wherein the photosensitive dry film resist is cured at a temperature of 180 ° C. or less to form an insulating protective layer.

  A printed wiring board according to the present invention is characterized by a method for producing a printed wiring board, wherein the photosensitive dry film resist is cured at a temperature of 160 ° C. or less to form an insulating protective layer.

  The photosensitive resin composition concerning this invention contains the specific polyamic acid, the (meth) acrylate compound which has a carbon-carbon double bond, and a photoinitiator as mentioned above. According to said structure, imidation at low temperature is possible compared with the conventional one, and it can be used for a rigid or FPC board | substrate use as a photosensitive dry film resist.

  Hereinafter, the photosensitive resin composition according to the present invention and the use thereof are specifically described in the order of (I) photosensitive resin composition, (II) a method of adjusting the photosensitive resin composition, and (III) use of the photosensitive resin composition. Explained.

(I) Photosensitive resin composition The photosensitive resin composition according to the present invention contains (A) a polyimide precursor, (B) a (meth) acrylate compound, and (C) a photoreaction initiator. It can be cured at temperatures below ℃. Hereinafter, although an example of the photosensitive resin composition concerning this invention is shown, this invention is not limited to those examples, (A) a polyimide precursor, (B) (meth) acrylate compound, and (C) It only needs to contain a photoinitiator and can be cured at a temperature of 180 ° C. or lower. More preferably, it can be cured at a temperature of 160 ° C. or lower.

  In the present invention, curing at a temperature of 180 ° C. or less means that the polyimide film Apical 25 NPI (manufactured by Kaneka) and a photosensitive dry film resist are laminated and exposed to a temperature of 180 ° C. in [Method for evaluating curing temperature] described later. The laminated body heated for 2 hours at high humidity was treated (stored in an environment of 85 ° C. and 85% RH for 48 hours), and the cross-cut peel (IPC TM650 2.4.28.1) of the laminated body before and after the high humidity treatment was measured. In Example 1, the case where no deterioration due to the high humidity treatment was observed was cured at a temperature of 180 ° C. or lower, that is, it was possible to cure. On the other hand, when the value of the cross-cut peel was lowered by the high-humidity treatment (when it was peeled off more), it was determined that it could not be cured at a temperature of 180 ° C. When the imidization of the polyimide precursor is not completed by heating at 180 ° C., the remaining polyamic acid site is hydrolyzed by the high-humidity treatment, resulting in embrittlement and peeling due to the cross-cut peel.

As an example of the photosensitive resin composition according to the present invention, (A) the polyimide precursor does not contain 10 mol% or more of the aromatic diamine containing a para bond in the total diamine, and the Tg after polyimide conversion is 200 ° C. or less. Some are listed. By setting it as such a structure, the photosensitive resin composition can be hardened | cured at the temperature of 180 degrees C or less.
Furthermore, each component which comprises the photosensitive resin composition concerning this invention is demonstrated in detail below.

  The polyimide precursor used in the present invention as the component (A) has the following general formula (1):

（式中、Ｒ¹は４価の有機基を示し、Ｒ²はメタ位で直接結合している芳香族化合物を示す。）で表される構成単位と一般式（２）

(Wherein R ¹ represents a tetravalent organic group and R ² represents an aromatic compound directly bonded at the meta position) and the general formula (2)

（式中、Ｒ¹は４価の有機基を示し、Ｒ³は一般式（３）か一般式（４）を示し、ただし、一般式（３）のＲ⁴は、−（ＣＨ₂）_n−であり、Ｒ⁵はメチル基かフェニル基であり、Ｒ⁵中のフェニル基の含有率が１５〜４０％でありｍは４〜２０の数で、ｎは２〜５の整数である。また、一般式（４）中Ｒ⁶はＨ，メチル基，エチル基，ブチル基を、ｒは１〜２０の整数を、ｓは０〜１０の整数を示す。）で表される構成単位を含むことにより、１８０℃以下の温度で硬化可能となる。

(In the formula, R ¹ represents a tetravalent organic group, R ³ represents the general formula (3) or the general formula (4), provided that R ^{4 in the} general formula (3) represents — (CH ₂ ) _n. R ⁵ is a methyl group or a phenyl group, the phenyl group content in R ⁵ is 15 to 40%, m is a number of 4 to 20, and n is an integer of 2 to 5. In the general formula (4), R ⁶ represents H, a methyl group, an ethyl group, or a butyl group, r represents an integer of 1 to 20, and s represents an integer of 0 to 10). By including, it can be cured at a temperature of 180 ° C. or lower.

一般式（１）中、Ｒ¹は４価の有機基であれば、特に限定されるものではないが、単環式の芳香族基、縮合多環式の芳香族基、およびこれらの芳香族基の２個以上が直接または連結基により連結された基から選択される炭素数６〜５０の４価の芳香族基であることがより好ましい。Ｒ¹としては、具体的には、例えば、後述する酸二無水物から、２つの−ＣＯ−Ｏ−ＣＯ−を除いた残基を挙げることができる。なお、Ｒ¹は一般式（１）で表される構成単位ごとに同一であってもよいし異なっていてもよい。

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

Examples of the diamine corresponding to the aromatic compound in which R ² is directly bonded at the meta position (hereinafter referred to as aromatic diamine directly bonded at the meta position) include m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminophenyl ether, 3,3′-diaminophenyl sulfide, 3,3′-diaminophenyl 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- Minophenoxy) benzene, 4,4′-bis (3-aminophenoxy) -biphenyl, 1,3-bis (3-aminophenoxy) benzene, bis [4- (3-aminophenoxy) phenyl] sulfone, 2 , 2-bis (3-aminophenyl) propane, 9,9-bis (3-aminophenyl) fluorene, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 4,6-diaminoresorcinol, 3,3 ′ -Diamino-4,4'-dihydroxybiphenyl, 3,3'-diamino-4,4'-dihydroxydiphenylmethane, 2,2-bis [3-amino-4-hydroxyphenyl] propane, 2,2-bis [3 -Amino-4-hydroxyphenyl] hexafluoropropane, 3,3'-diamino-4,4'-dihydroxydiphenyl ether, 3 , 3′-diamino-4,4′-dihydroxydiphenylsulfone, 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′-dicarboxydiphenyl sulfone, 3,5 -A compound obtained by removing the amino group of a diamine compound such as diaminobenzoic acid. This means all diamino compounds in which an amino group is directly bonded to an aromatic ring, and the amino group position is 3- or m-, and is not limited to the exemplified compounds. In particular, in order to obtain a photosensitive resin composition having high electrical reliability, it is desirable to select a compound having no hydroxyl group or carboxyl group among those exemplified above.

 Among the aromatic diamines directly bonded at these meta positions, m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminophenyl ether, 3,3′-diaminophenyl sulfide, 3, 3′-diaminophenylsulfone, 3,3′-diaminobenzanilide, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2 , 2-bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) -biphenyl, 1,3-bis (3-aminophenoxy) benzene Bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis (3-aminophenyl) propane is more preferable.

  The abundance ratio of the structural units of the general formula (1) and the general formula (2) is 10:90 to 90:10 in terms of mol% because it tends to have high heat resistance and adhesion, and preferably 20: It is 80-80: 20, More preferably, it is 30: 70-40: 60.

  The compound represented by the general formula (3) will be described. The diamine corresponding to the compound represented by the general formula (3) is hereinafter referred to as polysiloxane diamine, and is represented by the general formula (3 ').

一般式（３’）中、Ｒ⁴は、それぞれ独立して炭素数２ないし５のアルキレン基であればよい。具体的には、Ｒ⁴は、エチレン基、プロピレン基、テトラメチレン基またはペンタメチレン基である。

In general formula (3 ′), R ⁴ may be independently an alkylene group having 2 to 5 carbon atoms. Specifically, R ⁴ is an ethylene group, a propylene group, a tetramethylene group, or a pentamethylene group.

In general formula (3 ′), each R ⁵ is independently a methyl group or a phenyl group. The methyl group in R ⁵ may be partially substituted with an ethyl group or a propyl group as long as it does not adversely affect the performance of the resulting photosensitive resin composition. Here, the phenyl group content in R ⁵ is 15% or more and 40% or less. Photosensitive resin composition, photosensitive dry film resist and imidized product obtained when the phenyl group content in R ⁵ is lower than 15% (hereinafter referred to as photosensitive resin composition, etc. in this specification) ) Tends to decrease flame retardancy. On the contrary, the photosensitive resin composition obtained when the phenyl group content is 15% or more is excellent in flame retardancy, but when the phenyl group content is larger than 40%, the resulting photosensitive resin composition is obtained. Objects are not preferred because they tend to lack flexibility and low warpage. The content of the phenyl group is more preferably 18% or more and 38% or less, and further preferably 20% or more and 35% or less.

  Further, when the phenyl group content is outside the above range, the resulting photosensitive resin composition or the like tends to be inferior in photosensitivity, flexibility and electrical reliability. Thus, in the photosensitive resin composition according to the present invention, by setting the phenyl group content in the above range, the reason is not known, but the warpage is small and the flexibility, flexibility, electrical reliability, and photosensitivity are reduced. A photosensitive resin composition having excellent flame retardancy can be obtained.

  Moreover, since flame retardance improves, a large amount of flame retardant is not required like the polyimide precursor obtained using the conventional polysiloxane diamine. Therefore, it is possible to solve the problem of a decrease in electrical reliability due to a large amount of flame retardant.

Here, the phenyl group content means the molar fraction of the phenyl group contained in R ⁵ and is represented by the following formula.
The content of the phenyl group (%) = (R moles of phenyl groups in ⁵⁾ ÷ (moles of methyl groups of moles + R ⁵ of the phenyl group in R ⁵⁾ × 100
The content of methyl groups in R ⁵ is 85% or less than 60%. If the content of the methyl group in R ⁵ is lower than 60%, the resulting photosensitive resin composition is not preferred because it lacks flexibility and low warpage. On the contrary, the photosensitive resin composition obtained when the methyl group content is 60% or more is excellent in flexibility and low warpage, but when the methyl group content is more than 85%, the resulting photosensitive resin composition is excellent. This is not desirable because the flame retardancy of the functional resin composition and the like tends to decrease. The methyl group content is more preferably 62% to 82%, and still more preferably 65% to 80%.

  In general formula (3 ′), the number of repeating units m of the siloxane bond is preferably an integer of 4 or more and 20 or less. When m is smaller than 4, the flexibility / low warpage of the resulting photosensitive resin composition tends to decrease, and when m is larger than 20, the polysiloxane sites are aggregated in the obtained photosensitive resin composition, etc. Aggregated domains become longer than the wavelength of visible light, and light is diffusely reflected and whitened, resulting in a decrease in photosensitivity. Moreover, if m is larger than 20 and a large domain of only polysiloxane is formed, the flame retardancy is lowered. m is more preferably 4 or more and 18 or less, and further preferably 5 or more and 15 or less.

  Moreover, when the m is out of the above range, the resulting photosensitive resin composition or the like tends to be inferior in flexibility and electrical reliability. Thus, in the photosensitive resin composition according to the present invention, by setting m to the above range, the warpage is small, the flexibility, the flexibility, the electrical reliability, the photosensitivity, and the flame retardancy are excellent. A resin composition or the like can be obtained.

 The compound represented by the general formula (4) will be described. A diamine corresponding to the compound represented by the general formula (4) is represented by the general formula (4 ').

（一般式（４’）中、Ｒ⁶はＨ，メチル基，エチル基，ブチル基を、ｒは１〜２０の整数を、ｓは０〜１０の整数を示す。）
一般式（４’）に相当するジアミンを用いることにより電気信頼性・可撓性・屈曲性を付与することができる。

(In general formula (4 ′), R ⁶ represents H, a methyl group, an ethyl group, or a butyl group, r represents an integer of 1 to 20, and s represents an integer of 0 to 10.)
By using a diamine corresponding to the general formula (4 ′), electrical reliability, flexibility, and flexibility can be imparted.

  The weight average molecular weight of the polyimide precursor is preferably 2000 or more and 1000000 or less, and more preferably 5000 or more and 300000 or less. When the weight average molecular weight of the polyimide precursor is less than 2000, the resulting polyimide has a low molecular weight and tends to decrease the strength, and when it exceeds 1,000,000, the development time of the photosensitive resin tends to be long. Absent.

  Moreover, the weight average molecular weight / number average molecular weight of the polyimide precursor is preferably 1.5 or more and 10 or less, and more preferably 2 or more and 5 or less.

  Since the photosensitive resin composition according to the present invention contains the polyimide precursor, the resulting photosensitive resin composition has a small warpage and flexibility in a state where the photosensitive resin composition is laminated on an FPC as a photosensitive dry film resist. -The effect of this invention that it is excellent in a flexibility, electrical reliability, and photosensitivity and has a flame retardance can be acquired.

  In addition, if the photosensitive resin composition which concerns on this invention contains the polyimide precursor mentioned above, unless it has a bad influence on the performance of the photosensitive resin composition obtained, other polyimide precursors are used. May be included.

  Moreover, it is preferable that the content rate with respect to the whole photosensitive resin composition of a polyimide precursor is 10 to 90 weight% with respect to the whole photosensitive resin composition, and is 20 to 85 weight%. More preferably, it is 25 wt% or more and 80 wt% or less. Since the heat resistance of the photosensitive resin composition obtained by the content ratio of the polyimide precursor in the photosensitive resin composition being 10% or more tends to be improved, the content is preferably 90% or less. This is preferable because it enables pressure bonding to the material at a low temperature.

(A-2) Production method of polyimide precursor The production method of the polyimide precursor used in the present invention is not particularly limited as long as it has the above-described configuration. For example, acid dianhydride and An aromatic diamine directly bonded at the meta position and the polysiloxane diamine represented by the general formula (3 ′), or an aromatic diamine directly bonded at the meta position with the acid dianhydride and the general formula (4 ′) This diamine can be produced by reacting in a polar organic solvent.

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

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

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

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

  The above acid dianhydride, aromatic diamine and polysiloxane diamine bonded directly at the meta position, or aromatic diamine bonded directly to the acid dianhydride at the meta position and the diamine of the general formula (4 ′) are organic The order in which the reaction is carried out in a polar solvent is not particularly limited, and an acid dianhydride, a polysiloxane diamine (or a diamine of the general formula (4 ′)) and an aromatic diamine directly bonded at the meta position are simultaneously reacted. Or after starting the reaction between the acid dianhydride and the polysiloxane diamine (or the diamine of the general formula (4 ′)), the reaction may be performed by adding another aromatic diamine, After the reaction between the acid dianhydride and the aromatic diamine directly bonded at the meta position is first started, polysiloxane diamine (or the diamine of the general formula (4 ′)) may be added and reacted.

  Among them, it is more preferable to start the reaction between the acid dianhydride and the polysiloxane diamine (or the diamine of the general formula (4 ′)) and then add the aromatic diamine directly bonded at the meta position to cause the reaction. .

  In such a case, first, acid dianhydride and polysiloxane diamine (or diamine of general formula (4 ′)) may be reacted in an organic polar solvent. For example, acid dianhydride and organic polar solvent Polysiloxane diamine (or diamine of general formula (4 ′)) or a solution thereof may be added to a solution or suspension solution consisting of Subsequently, the polyimide precursor (polyamic acid) used in the present invention can be synthesized by adding an aromatic diamine directly bonded at the meta position thereto.

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

At this time, the reaction between the acid dianhydride and the polysiloxane diamine (or the diamine of the general formula (4 ′)) is preferably performed in the organic polar solvent under a temperature condition of −20 ° C. or more and 80 ° C. or less. It is more preferable to carry out the reaction under a temperature condition of −15 ° C. or more and 50 ° C. or less.
By setting the reaction temperature to −20 ° C. or higher, the acid dianhydride and the polysiloxane diamine (or the diamine of the general formula (4 ′)) can be reacted. In addition, the reaction time when the acid dianhydride and the polysiloxane diamine (or the diamine of the general formula (4 ′)) are reacted is not particularly limited, but may be, for example, 1 to 12 hours. preferable.

  In this case, the number of moles of acid dianhydride to be reacted is preferably larger than the number of moles of polysiloxane diamine (or diamine of the general formula (4 ')). Thereby, the polyimide precursor (polyamic acid) oligomer of an acid dianhydride terminal can be obtained.

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

  When the aromatic diamine directly bonded at the meta position exceeds 90 mol% of the total diamine, the imidization temperature tends to be increased, so 90 mol% or less is preferable, and 80 mol% or less is more preferable.

  In the polyimide precursor of the present invention, the logarithmic viscosity at 30 ° C. of a solution of 5 g / l N-methylpyrrolidone is preferably in the range of 0.2 to 4.0, and in the range of 0.3 to 2.0. It is more preferable that

(B) (Meth) acrylate Compound The (meth) acrylic compound used in the present invention is not particularly limited as long as it has a carbon-carbon double bond. Specific examples of the (meth) acrylic compound include, for example, bisphenol F EO-modified (n = 2 to 50) diacrylate, bisphenol A EO-modified (n = 2 to 50) diacrylate, and sphenol S EO-modified ( n = 2-50) Diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate , Tetramethylolpropane tetraacrylate, tetraethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene Recall dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, tetramethylolpropane tetramethacrylate, tetraethylene glycol dimethacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacrylic Iroxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro-2-hydroxypropyl methacrylate, stearyl methacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate , 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-hexane Diol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy 1,3 dimethacryloxypropane, 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4 -(Methacryloxy / diethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy / polyethoxy) phenyl] propane, polyethylene glycol Rudicrylate, 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, isosteary Acrylate, polyoxyethylene alkyl ether acrylate, nonylphenoxyethylene glycol acrylate, polypropylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 3-methyl-1,5-pentanediol dimethacrylate, 1,6-mexanediol 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- Ethyl-1,5-pentanediol diacrylate, ethoxylated tomethylolpropane triacrylate, propoxylated tomethylolpropane triacrylate, isocyanuric acid tri (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, propoxy 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, alloruby Tal, diallylamine, diallyldimethylsilane, diallyl disulfide, diallyl ether, zalyl sialate, diallyl isophthalate, diallyl terephthalate, 1,3-dialyloxy-2-propanol, diallyl sulfide diallyl maleate, 4,4'-isopropylidenediphenol Examples include dimethacrylate, 4,4′-isopropylidene diphenol diacrylate, and the like. In order to improve the crosslinking density, it is particularly preferable to use a bifunctional or higher monomer.

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

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

  The (meth) acrylic compound is preferably blended in the range of 1 to 400 parts by weight, preferably in the range of 3 to 300 parts by weight with respect to 100 parts by weight of the polyimide precursor. Further preferred. By mix | blending within the said range, the photosensitive resin composition which imidizes at low temperature compared with the conventional thing can be implement | achieved especially effectively.

(C) Photoreaction initiator In this specification, "photoreaction initiator" is a general term for compounds that generate radicals upon irradiation with light. Although the photoinitiator used by this invention will not be specifically limited if it is a compound which generate | occur | produces a radical by light irradiation, It is preferable that it is a compound which generate | occur | produces a radical by light irradiation of 250-450 nm. Specific examples of such photoreaction initiators include the following general formulas (5) and (6).

（一般式式（５）および（６）中、Ｒ⁷、Ｒ⁸、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹、およびＲ¹²は、Ｃ₆Ｈ₅−、Ｃ₆Ｈ₄（ＣＨ₃）−、Ｃ₆Ｈ₂（ＣＨ₃）₃−、（ＣＨ₃）₃Ｃ−、Ｃ₆Ｈ₃Ｃｌ₂−、メトキシ基、またはエトキシ基を示す。）
で表されるアシルフォスフィンオキシド化合物を挙げることができる。これにより発生したラジカルは、２重結合を有する反応基（ビニル、アクロイル、メタクロイル、またはアリル等）と反応し架橋を促進することができる。

(In the general formulas (5) and (6), R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² are C ₆ H ₅ —, C ₆ H ₄ (CH ₃ ) —, C ₆ H ₂ (CH ₃ ) ₃ —, (CH ₃ ) ₃ C—, C ₆ H ₃ Cl ₂ —, a methoxy group, or an ethoxy group.
The acyl phosphine oxide compound represented by these can be mentioned. The radicals generated thereby can react with a reactive group having a double bond (such as vinyl, acroyl, methacryloyl, or allyl) to promote crosslinking.

  The acyl phosphine oxide represented by the general formula (5) generates two radicals, whereas the acyl phosphine oxide represented by the general formula (6) Generate radicals. Therefore, in this invention, it is more preferable to use the acyl phosphine oxide represented by the said General formula (6).

  Moreover, the photosensitive resin composition concerning this invention WHEREIN: It is preferable that the said photoreaction initiator contains 0.01-50 weight part with respect to 100 weight part of said polyimide precursors.

  Moreover, in the photosensitive resin composition concerning this invention, you may use it combining a peroxide and a sensitizer as said photoreaction initiator. By setting it as this structure, the photosensitive resin composition can achieve the photosensitivity which can be provided to practical use.

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

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

  The sensitizer may be blended within a range where a sensitizing effect is obtained and the developability is not adversely affected. Specifically, it is preferable to mix 0.01-50 weight part with respect to 100 weight part of polyimide precursors of this invention, and it is still more preferable to mix | blend 0.1-20 weight part. In addition, as a sensitizer, one type of compound may be used and two or more types of compounds may be mixed and used. The peroxide is preferably blended in an amount of 1 to 200 parts by weight, more preferably 1 to 150 parts by weight, based on 100 parts by weight of the sensitizer.

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

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

  The photopolymerization assistant may be blended within a range where a sensitizing effect is obtained and the developability is not adversely affected. Specifically, it is preferable to mix 0.01 to 50 parts by weight with respect to 100 parts by weight of the polyimide precursor of the present invention, and a range of 0.1 to 20 parts by weight is more preferable.

(D) Phosphorus flame retardant The photosensitive resin composition according to the present invention contains a flame retardant in addition to the polyimide precursor, the (meth) acrylic compound, and the photoreaction initiator. In the present specification, the “flame retardant” means a substance that acts to make a flammable substance difficult to burn by adding or reacting with a flammable substance such as plastic, wood, or fiber.

  The content of the flame retardant is not particularly limited, and may be appropriately selected according to the type of flame retardant used. In general, the content of the flame retardant is preferably in the range of 5 to 50% by weight when the total amount of the polyimide precursor and the (meth) acrylic compound is 100% by weight, and 10 to 40% by weight. % Is more preferable. By using a flame retardant within such a range, flame retardancy can be effectively imparted to the cured coverlay film. Furthermore, the mechanical properties of the coverlay film after curing can be improved.

  Among these, the flame retardant used in the present invention is preferably a flame retardant containing phosphorus (hereinafter referred to as “phosphorous flame retardant”).

  When a phosphorus flame retardant is used as the flame retardant, the phosphorus content of the phosphorus flame retardant is preferably 5.0% by weight or more when the phosphorus flame retardant is 100, and is 7.0% by weight or more. More preferably. By using such a phosphorus flame retardant, flame retardancy can be effectively imparted.

  Examples of the phosphorus flame retardant include phosphorus compounds such as phosphazene, phosphine, phosphine oxide, phosphate ester (including condensed phosphate ester), and phosphite ester. In particular, from the viewpoint of compatibility with the photosensitive resin composition, phosphazenes, condensed phosphates, and the like can be preferably used.

  Specific examples of such phosphorus-based flame retardants include, for example, SPE-100 (phosphazene compound manufactured by Otsuka Chemical), SPH-100 (Otsuka Chemical Co., Ltd.) because they can impart flame retardancy and have hydrolysis resistance. Phosphazene compound), TPP (triphenyl phosphate) (manufactured by Daihachi Chemical), TCP (tricresyl phosphate) (manufactured by Daihachi Chemical), TXP (trixylenyl phosphate) (manufactured by Daihachi Chemical), CDP (cresyl) Phosphoric acid esters such as diphenyl phosphate (made by Daihachi Chemical), PX-110 (cresyl 2,6-xylenyl phosphate) (made by Daihachi Chemical); CR-733S (resorcinol-diphosphate) (made by Daihachi Chemical) ), CR-741 (manufactured by Daihachi Chemical), CR-747 (manufactured by Daihachi Chemical), PX-200 (manufactured by Daihachi Chemical), and the like. Examples include acid esters.

  The photosensitive resin composition concerning this invention should just contain (A) polyimide precursor, (B) (meth) acrylate compound, (C) photoreaction initiator, and (D) phosphorus flame retardant. However, it may contain other components as long as the performance is not deteriorated. Examples of such other components include a filler, a storage stabilizer, and an ion scavenger.

(II) Method for adjusting photosensitive resin composition The photosensitive resin composition according to the present invention includes a polyimide precursor, a (meth) acrylic compound, a photoreaction initiator, a phosphorus flame retardant, and other components as necessary. It can be obtained by mixing the components.

  Moreover, the photosensitive resin composition concerning this invention can be melt | dissolved and used for an organic solvent. An organic solvent solution of the photosensitive resin composition (hereinafter sometimes referred to as a photosensitive resin composition solution in the present specification) can be obtained by uniformly dissolving the photosensitive resin composition in an organic solvent. it can.

  The organic solvent is not particularly limited as long as it is an organic solvent that can dissolve the components contained in the photosensitive resin composition. Examples of the organic solvent include amide solvents such as dimethylacetamide and dimethylformamide, 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. Etc. These organic solvents may be used alone or in combination of two or more.

  The amount of the organic solvent used is not particularly limited as long as it does not adversely affect workability, drying properties, performance of the photosensitive resin composition, and the like. Preferably, the organic solvent to be used is preferably 30 parts by weight or more and 1000 parts by weight or less, and more preferably 50 parts by weight or more and 500 parts by weight or less with respect to 100 parts by weight of the photosensitive resin composition.

  In addition, when using the organic solvent solution of the said photosensitive resin composition for the photosensitive dry film resist etc. which are mentioned later, the said organic solvent can melt | dissolve the component contained in the said photosensitive resin composition, and has a boiling point. It is preferable to select a low one. Thereby, the energy and time for performing the removal of an organic solvent can be reduced.

(III) Use of photosensitive resin composition The photosensitive resin composition according to the present invention is a photosensitive dry film resist obtained by coating a photosensitive resin composition solution on a support film and drying it. It can be used as a coverlay film that protects a conductor surface such as an FPC. Therefore, the present invention also includes a photosensitive dry film resist obtained from the above-described photosensitive resin composition and a printed wiring board formed by forming the photosensitive dry film resist as an insulating protective layer.

  The use of the photosensitive resin composition of the present invention is not limited to the photosensitive dry film resist, and the photosensitive resin composition solution may be directly applied to FPC or the like and dried to be used as a coverlay film. Good. Furthermore, in addition to the coverlay film, it can be used for applications such as rigid printed circuit board solder resists and build-up insulating films.

  Hereinafter, the photosensitive dry film resist and printed wiring board according to the present invention will be described.

(III-1) Photosensitive dry film resist The photosensitive dry film resist according to the present invention is a photosensitive dry film resist obtained by using the photosensitive resin composition of the present invention. It is produced by uniformly applying and drying on a support film. Specifically, the above photosensitive resin composition solution is uniformly applied on a support film, and then heated and / or hot air sprayed. Thereby, the photosensitive resin composition solution is dried, that is, the organic solvent of the photosensitive resin composition solution is removed, and a photosensitive dry film resist in which the photosensitive resin composition is formed into a film can be obtained.

  In the present specification, the photosensitive dry film resist means a layer of the photosensitive resin composition in a film form, and does not mean a laminate with a support film or the like. In addition, the photosensitive dry film resist concerning this invention may exist in the state formed on the support body film, and is one of the three-layer structure sheets of the support body film and protective film mentioned later. It may exist as a layer, or may exist in a state of being laminated on an FPC or the like.

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

  The film thickness of the support film is preferably 10 μm or more and 125 μm or less, and more preferably 15 μm or more and 50 μm or less.

  Moreover, the method for applying the photosensitive resin composition solution to the support film is not particularly limited, and a method such as reverse coating, gravure coating, die coating, comma coating, spray coating, or the like is preferably used. it can.

  The temperature at which the photosensitive resin composition solution is dried by performing the above heating and / or hot air blowing is not particularly limited. For example, the (meth) acrylic compound contained in the photosensitive resin composition, etc. It is sufficient that the temperature is such that the curable group does not react. Specifically, the temperature is preferably 50 ° C. or higher and 150 ° C. or lower, and more preferably 60 ° C. or higher and 130 ° C. or lower. The drying time is preferably shorter as long as the organic solvent can be removed. Usually, the drying time is 0.5 to 30 minutes. Moreover, the film thickness of the photosensitive resin composition after drying, that is, the film thickness of the photosensitive dry film resist is preferably 5 μm or more and 75 μm or less, and more preferably 10 μm or more and 60 μm or less.

  The photosensitive dry film resist produced in this way is obtained by keeping the photosensitive resin composition in a semi-cured state (B stage). Therefore, when thermocompression treatment such as thermal lamination treatment is performed, the pattern circuit of the printed wiring board can be suitably embedded with appropriate fluidity. Moreover, after embedding the pattern circuit, it can be completely cured by performing an exposure process, a thermocompression bonding process, or a heating cure.

  Moreover, it is preferable to laminate | stack a protective film further on the photosensitive dry film resist produced by apply | coating the photosensitive resin composition to a support body film, and drying. Thereby, it is possible to prevent dust and dust in the air from adhering and to prevent deterioration of quality due to drying of the photosensitive dry film resist.

  The protective film is preferably laminated and laminated on the photosensitive dry film resist surface. 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 for the protective film is not particularly limited. For example, polyethylene film (PE film), polyethylene vinyl alcohol film (EVA film), “copolymer film of polyethylene and ethylene vinyl alcohol” (hereinafter, (Also referred to as “(PE + EVA) copolymer film”), “bonded body of PE film and (PE + EVA) copolymer film”, or “film by simultaneous extrusion production method of (PE + EVA) copolymer and polyethylene” ( And the other surface can be a film having a PE film surface and a PE film surface).

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

(III-2) Printed wiring board The printed wiring board according to the present invention is a printed wiring board formed by forming the photosensitive dry film resist as an insulating protective layer. The case of using a CCL formed with a pattern circuit (hereinafter also referred to as “CCL with circuit”) as a printed wiring board will be described as an example, but the same applies to the case of forming a multilayer printed wiring board. An interlayer insulating layer can be formed by this method.

  For example, the protective film is peeled off from the three-layer structure sheet having the protective film, the photosensitive dry film resist, and the support film described in (III-1). Below, what peeled off the protective film is described as "the photosensitive dry film resist with a support film". Then, the CCL with a circuit is covered with the photosensitive dry film resist with a support film and bonded by thermocompression bonding so that the photosensitive dry film resist and the circuit portion of the CCL with circuit are opposed to each other. The method of bonding by thermocompression bonding is not particularly limited, and may be performed by hot pressing, laminating (thermal laminating), hot roll laminating, or vacuum laminating.

  When the bonding is performed by heat laminating or hot roll laminating (hereinafter also referred to as “laminating”), the processing temperature is also referred to as the lower limit temperature at which laminating is possible (hereinafter also referred to as “pressure bonding temperature”). ) Or more. Moreover, the upper limit of the said processing temperature should just be temperature lower than the temperature which the crosslinking reaction of the photosensitive reactive group contained in the photosensitive dry film resist occurs at the time of a lamination process. On the other hand, the lower limit of the processing temperature may be any temperature as long as the photosensitive dry film resist has suitable fluidity and can embed the pattern circuit suitably.

  Specifically, the treatment temperature is preferably in the range of 50 to 150 ° C, more preferably in the range of 60 to 120 ° C, and more preferably in the range of 80 to 120 ° C. . When the said process temperature exists in the said range, high adhesiveness with the copper circuit of CCL with a copper circuit or the base film of the said CCL with a copper circuit is realizable.

  In addition, it is preferable to apply pressure in the thermocompression treatment including laminating. The pressure is preferably 100 Pa · m or more and 1000000 Pa · m or less, and more preferably 1000 Pa · m or more and 100000 Pa · m or less. When the applied pressure is within the above range, the photosensitive dry film can be suitably adhered without protruding.

  By the above thermocompression treatment, a laminate in which a photosensitive dry film resist is laminated on the CCL with a circuit and a support film is further laminated is obtained. Next, pattern exposure and development are performed on this laminate. In pattern exposure and development, a photomask pattern is placed on the support film of the laminate, 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.

  The support film may be peeled off after the exposure process as described above, or after the photosensitive dry film resist with the support film is bonded onto the CCL with circuit, that is, before the exposure process is performed. Alternatively, it may be peeled off. 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 300 to 430 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 the solvent can dissolve the basic compound. Among them, it is particularly preferable to use water from the viewpoint of environmental problems.

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

  The concentration of the basic compound contained in the basic solution is preferably in the range of 0.1 to 10% by weight, and 0.1 to 5% by weight from the viewpoint of alkali resistance of the photosensitive dry film resist. It is more preferable to be within the range.

  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.

  The liquid temperature of the basic solution is preferably 10 ° C. or higher and 50 ° C. or lower, and more preferably 25 ° C. or higher and 45 ° C. or lower.

  In the present invention, in particular, a developing treatment using a 1% by weight sodium carbonate aqueous solution whose liquid temperature is adjusted to 40 ° C. as a developer and using a spray developing machine can be suitably used. The “spray developer” here is not particularly limited as long as it is a device that sprays a developer on a sample.

  The development time until the pattern of the photosensitive dry film resist can be drawn only needs to be a time for drawing the pattern. For example, development can be performed in a time of 180 seconds or less, development is more preferable in a time of 90 seconds or less, and development is particularly preferable 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 a 1 wt% sodium carbonate aqueous solution (liquid temperature 40 ° C.) is used as a developer, with a spray pressure of 0. This is a method of performing spray development at 85 MPa. 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.

  As described above, after the exposure / development treatment is performed, the photosensitive dry film resist is completely cured (imidized) 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. The temperature at which the heat curing is performed, that is, the imidization temperature is preferably 120 ° C. or higher and 180 ° C. or lower, more preferably 120 ° C. or higher and 160 ° C. or lower, or 140 ° C. or higher and 180 ° C. or lower, and 140 ° C. More preferably, it is 160 degreeC or less. As described above, the photosensitive resin composition according to the present invention can be imidized at a lower imidization temperature as compared with conventional photosensitive polyimide, and has low warpage, flexibility, flexibility, It has unprecedented performance that combines electrical reliability, photosensitivity and flame retardancy. Thus, a photosensitive resin composition satisfying all of the low imidization temperature, low warpage, flexibility, flexibility, electrical reliability, photosensitivity, and flame retardancy has never been achieved, and is achieved for the first time in the present invention. It is a thing.

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

  In the present embodiment, the case where the photosensitive dry film resist is used as an insulating protective material or an interlayer insulating material of a printed wiring board has been described, but the present invention is not limited to each configuration described above, Embodiments obtained by appropriately combining the disclosed technical means are also included in the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by an Example.

  In addition, the molecular weight of the polyimide precursor in an Example and a comparative example, Tg of what polyimide-ized the polyimide precursor, the adhesiveness of the photosensitive resin composition or the photosensitive dry film resist after imidation, solder heat resistance, photosensitivity Evaluation methods for migration resistance and curing temperature are as follows.

[Molecular weight of polyimide precursor and polyimide]
The molecular weight of the polyimide precursor was measured using a high-speed GPC (trade name HLC-8220 GPC, manufactured by Tosoh Corporation). The measurement conditions were DMF (0.036M LiBr, 0.019M phosphoric acid included) as a developing solvent, Tosoh made as a column, trade name: TSK gel Super AWM-H, using a column temperature of 40 ° C., detection RI (PEO, PEG standard) was used as the vessel, and the flow rate was 0.6 ml / min.
[Tg of polyimide precursor converted to polyimide]
The obtained polyimide precursor solution was applied to a glass plate, heated at 100 ° C. for 30 minutes and 250 ° C. for 30 minutes, and then peeled off from the glass plate to obtain a polyimide film having a thickness of about 25 μm. This polyimide film was measured using TMA120C manufactured by SII Nanotechnology Co., Ltd. at a heating rate of 10 ° C./min, and the inflection point temperature of the obtained chart was defined as Tg.
[Crosscut peel]
The photosensitive resin composition solution was applied onto a PET film (thickness 25 μm) so that the thickness after drying was 25 μm, dried to remove the organic solvent, and a photosensitive dry film resist was obtained. (Drying conditions are 1 minute at 90 ° C. after drying for 1 minute at 60 ° C. when the solvent is dioxolane, and 10 minutes at 100 ° C. when the solvent is N-methylpyrrolidone and N, N′-dimethylformamide.) Polyimide film Apical 25 NPI (manufactured by Kaneka) and a photosensitive dry film resist were combined and laminated under the conditions of 110 ° C. and 20000 Pa · m. Subsequently, 400 m light was exposed by 300 mJ / cm ² , and then the PET film was peeled off and heated at 180 ° C. for 2 hours to obtain a laminate. About this laminated body, adhesiveness evaluation was performed according to the test of the crosscut peel of IPC TM650 2.44.28.1.

[Solder heat resistance]
A photosensitive dry film resist prepared in the same manner as the measurement item of the cross-cut peel was laminated to the bright surface of the electrolytic copper foil (3EC-VLP 1 ounce made by Mitsui Metals) at 100 ° C. and 20000 Pa · m. Subsequently, 400 m light was exposed by 300 mJ / cm ² , and then the PET film was peeled off and heated at 180 ° C. for 2 hours to obtain a laminate. This laminate was conditioned at 40 ° C. and 95% RH for 24 hours, then immersed in a solder bath for 10 seconds, and the presence or absence of surface swelling and discoloration was observed. The maximum temperature without swelling and discoloration was defined as the solder heat resistance temperature.

[Photosensitivity]
A photosensitive dry film resist prepared in the same way as the measurement item of the crosscut peel was laminated on the bright surface of electrolytic copper foil (Mitsui Metals 3EC-VLP 1 ounce) and laminated at 100 ° C. and 20000 Pa · m while being shielded from light. A laminated body was obtained.

A mask pattern was placed on the laminate, and 400 nm light was exposed by 300 mJ / cm ² and developed with a 1 wt% aqueous sodium carbonate solution (liquid temperature 35 ° C.). The photomask pattern depicts fine holes of 500 μmφ, 200 μmφ, and 100 μmφ and lines having a line / space of 500 μm / 500 μm, 200 μm / 200 μm, and 100 μm / 100 μm. The pattern formed by development was then washed with distilled water to remove the developer.

[Migration resistance of photosensitive resin composition, etc.]
Line / space = 25/25 μm shown in FIG. 1 on Nippon Steel Chemical's flexible copper-clad laminate (single-sided copper-clad laminate having a copper foil on one side of a polyimide resin: SC18-25-00FR) The comb pattern was formed.

On this comb pattern, a photosensitive dry film resist prepared in the same manner as in the measurement item of the crosscut peel was superposed and laminated at 100 ° C. and 20000 Pa · m. Subsequently, 400 mJ / cm ² of 400 nm light was exposed, and then the PET film was peeled off and heated at 180 ° C. for 2 hours to obtain a laminate.

  In an environmental test machine at 85 ° C. and 85% RH, a DC voltage of 60 V was applied to both terminals of the comb pattern covered with the obtained laminate, and changes in resistance and presence / absence of migration were observed.

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

[Sliding bending]
Line / space = 250/250 μm shown in FIG. 2 on Nippon Steel Chemical's flexible copper-clad laminate (single-sided copper-clad laminate having a copper foil on one side of a polyimide resin: SC18-25-00FR) The sliding bending pattern was formed.

On this pattern, a photosensitive dry film resist prepared in the same manner as in the measurement item of the cross-cut peel was superposed and laminated at 100 ° C. and 20000 Pa · m. 400 nm light was exposed by 400 mJ / cm ² , and then the PET film was peeled off and heated at 180 ° C. for 2 hours to obtain a laminate.

  This laminate was set in a test apparatus (FPC bending test apparatus “SEK-31B4” manufactured by Shin-Etsu Engineering Co., Ltd.) so that the coverlay film side was on the outside, and a radius of curvature; R = 2.5 mm, a stroke: a width of 15 mm, The test was performed at a test speed of 1500 times (reciprocating) / minute, and the number of bendings was measured. At this time, a current of 1 mA was supplied to the laminated body, the resistance value was measured, and when the initial resistance value was increased by 50%, it was assumed that it was disconnected and stopped.

[Flame retardance: photosensitive resin composition, etc.]
A photosensitive dry film resist prepared in the same manner as the item of measurement of photosensitivity was superimposed on polyimide film Apical 25 NPI (manufactured by Kaneka) and laminated under the conditions of 110 ° C. and 20000 Pa · m. Subsequently, 400 nm light was exposed by 300 mJ / cm ² , the PET film was peeled off, and heated at 180 ° C. for 2 hours to obtain a laminate.

  This laminate was tested according to the UL94 thin material vertical combustion test (VTM-0).

[Evaluation method of curing temperature]
The laminate obtained in the same manner as the measurement item of the crosscut peel is stored for 48 hours in an environment of 85 ° C. and 85% RH. Cross-cut peel measurement of the laminate before and after high humidity treatment (referred to as high humidity treatment) is performed. If peeling occurred due to the high humidity treatment, imidation of the polyimide precursor was not completed and hydrolysis occurred, and it was judged that the curing was completely insufficient at a temperature of 180 ° C.

[Synthesis of polyimide precursor]
As raw materials for polyimide, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (hereinafter also referred to as “BTDA”), 3,3 ′, 4,4′-biphenyl as acid dianhydride Ether tetracarboxylic dianhydride (hereinafter also referred to as “ODPA”), pyromellitic dianhydride, 3,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (hereinafter also referred to as “s-BPDA”) 4,4′-bis (3-aminophenoxy) biphenyl, 1,3-bis (3-aminophenoxy) benzene, and 3,3′-diaminophenyl ether were used as aromatic diamines. As the solvent, N-methylpyrrolidone (hereinafter also referred to as “NMP”), N, N′-dimethylformamide (hereinafter also referred to as “DMF”) and dioxolane were used.

Example 1
<Synthesis of polyimide precursor>
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, 59.68 g (40 mmol: R in the general formula (3), polysiloxane diamine X-22-9409S manufactured by Shin-Etsu Chemical Co., Ltd. ² = propylene group, m = about 12, phenyl group content 25%, molecular weight 1492) was dissolved in 59.68 g of dioxolane and added at room temperature for 1 hour. Next, 17.54 g (60 mmol) of 1,3-bis (3-aminophenoxy) benzene was added, and stirring was continued for 3 hours to obtain a polyimide precursor.

  When the molecular weight of the obtained polyimide precursor was measured, the weight average molecular weight was 80000, the number average molecular weight was 32000, and the weight average molecular weight / number average molecular weight was 2.5.

  The Tg of the polyimide precursor converted to a polyimide was 90 ° C.

<Adjustment of photosensitive resin composition>
The components shown below were mixed to prepare a photosensitive resin composition, and dioxolane was added so that the solid content concentration was 30% by weight to prepare a photosensitive resin composition solution.
(A) 60 parts by weight of the polyimide precursor synthesized above (substantially part by weight of the solid content of the polyimide precursor)
(B) (meth) acrylic compound having an unsaturated double bond Daicel Cytec EB150 10 parts by weight Hitachi Chemical Co., Ltd. FA321M (polyethylene glycol-modified bisphenol A dimethacrylate) 5 parts by weight Toagosei Co., Ltd. M211B 10 parts by weight (C) Photoinitiator bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide 2 parts by weight (D) Phosphorus flame retardant: phosphazene compound SPH-100 by Otsuka Chemical Co., Ltd. 15 parts by weight < Evaluation of photosensitive dry film resist after imidization>
All 100 cross-cut peels remained and passed. The solder heat resistance temperature was 290 ° C. As for the photosensitivity, a hole of 100 μmφ and a line / space of 100 μm / 100 μm were drawn, and the photosensitivity was good. The migration resistance showed a resistance of 10 ¹⁰ Ω or more even after 1000 hours, and no discoloration or dendrite was observed in the pattern, which was very good. The warpage was 0 mm and there was no warpage. The sliding bending was very good as observed 20 million times. Flame retardancy (photosensitive resin composition etc.) was equivalent to VTM-0.

  Moreover, according to the measuring method of hardening temperature, when the crosscut peel after high-humidity processing was measured, all 100 pieces remained and it was a pass. Therefore, it was confirmed that the resin was completely cured at a curing temperature of 180 ° C.

  In the measurement section of the crosscut peel, a laminate is obtained by heating at 180 ° C. for 2 hours, but this temperature is lowered to 160 ° C., and a laminate is prepared. When 100 cross-cut peel measurements were made, all 100 pieces remained and passed. Therefore, it was confirmed that the resin was completely cured (imidized) at a low temperature of 160 ° C.

(Example 2)
<Synthesis of polyimide precursor>
In a 2000 ml separable flask equipped with a stirrer, 32.22 g (100 mmol) of BTDA and 112.5 g of DMF were taken, and 80.88 g (30 mmol of polysiloxane diamine: R ² = propylene group in the general formula (3), m was about 20, phenyl group content 40%, molecular weight 2696) dissolved in DMF 80.88 g, and stirring was continued for 2 hours at room temperature, followed by 15.83 g (70 mmol) of 2,2-bis (3-aminophenyl) propane. In addition, stirring was continued for 3 hours to obtain a polyimide precursor.

  When the molecular weight of the obtained polyimide precursor was measured, the weight average molecular weight was 60000, the number average molecular weight was 25000, and the weight average molecular weight / number average molecular weight was 2.4.

  The Tg of the polyimide precursor converted to a polyimide was 100 ° C.

<Adjustment of photosensitive resin composition>
A photosensitive resin composition was prepared in the same manner as in Example 1 except that the polyimide precursor was changed to that synthesized in this example.

<Evaluation of photosensitive dry film resist after imidization>
All 100 cross-cut peels remained and passed. The solder heat resistance temperature was 280 ° C. As for the photosensitivity, a hole of 100 μmφ and a line / space of 100 μm / 100 μm were drawn, and the photosensitivity was good. The migration resistance showed a resistance of 10 ¹⁰ Ω or more even after 1000 hours, and no discoloration or dendrite was observed in the pattern, which was very good. Warpage was good at 1 mm. The sliding bending was very good as observed 10 million times. Flame retardancy (photosensitive resin composition etc.) was equivalent to VTM-0.

  Moreover, according to the measuring method of hardening temperature, when the crosscut peel after high-humidity processing was measured, all 100 pieces remained and it was a pass. Therefore, it was confirmed that the resin was completely cured at a curing temperature of 180 ° C.

  In the measurement section of the crosscut peel, a laminate is obtained by heating at 180 ° C. for 2 hours, but this temperature is lowered to 160 ° C., and a laminate is prepared. When 100 cross-cut peel measurements were made, all 100 pieces remained and passed. Therefore, it was confirmed that the resin was completely cured (imidized) at a low temperature of 160 ° C.

(Example 3)
<Synthesis of polyimide precursor>
In a 500 ml separable flask equipped with a stirrer, 35.82 g (100 mmol) of 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride and 83.0 g of DMF were taken, and 1,2-bis (2- 5.93 g (40 mmol) of aminoethoxy) ethane was dissolved in 5.93 g of DMF and stirred at room temperature for 2 hours, and then 17.54 g (60 mmol) of 1,3-bis (3-aminophenoxy) benzene was added. Stirring was continued for a time to obtain a polyimide precursor.

  When the molecular weight of the obtained polyimide precursor was measured, the weight average molecular weight was 85000, the number average molecular weight was 30000, and the weight average molecular weight / number average molecular weight was 2.8.

  The Tg of the polyimide precursor converted to polyimide was 130 ° C.

<Adjustment of photosensitive resin composition>
A photosensitive resin composition was prepared in the same manner as in Example 1 except that the polyimide precursor was changed to that synthesized in this example.

<Evaluation of photosensitive dry film resist after imidization>
All 100 cross-cut peels remained and passed. The solder heat resistance temperature was 280 ° C. As for the photosensitivity, a hole of 100 μmφ and a line / space of 100 μm / 100 μm were drawn, and the photosensitivity was good. The migration resistance showed a resistance of 10 ¹⁰ Ω or more even after 1000 hours, and no discoloration or dendrite was observed in the pattern, which was very good. Warpage was good at 1 mm. The sliding bending was very good as observed 10 million times. Flame retardancy (photosensitive resin composition etc.) was equivalent to VTM-0.
Moreover, according to the measuring method of hardening temperature, when the crosscut peel after high-humidity processing was measured, all 100 pieces remained and it was a pass. Therefore, it was confirmed that the resin was completely cured at a curing temperature of 180 ° C.

Example 4
<Synthesis of polyimide precursor>
In a 2000 ml separable flask equipped with a stirrer, 31.02 g (100 mmol) of ODPA and 81.7 g of dioxolane were taken, and 4.09 g (40 mmol) of 1,3-diamino-2,2-dimethylpropane was added to 4.09 g of dioxolane. After dissolution, the mixture was stirred at room temperature for 1 hour. Next, 22.11 g (60 mmol) of 4,4′-bis (3-aminophenoxy) biphenyl was added and stirring was continued for 3 hours to obtain a polyimide precursor.

  When the molecular weight of the obtained polyimide precursor was measured, the weight average molecular weight was 85000, the number average molecular weight was 30000, and the weight average molecular weight / number average molecular weight was 2.8.

  The Tg of the polyimide precursor that was converted to polyimide was 140 ° C.

<Adjustment of photosensitive resin composition>
A photosensitive resin composition was prepared in the same manner as in Example 1 except that the polyimide precursor was changed to that synthesized in this example.

<Evaluation of photosensitive dry film resist after imidization>
All 100 cross-cut peels remained and passed. The solder heat resistance temperature was 280 ° C. As for the photosensitivity, a hole of 100 μmφ and a line / space of 100 μm / 100 μm were drawn, and the photosensitivity was good. The migration resistance showed a resistance of 10 ¹⁰ Ω or more even after 1000 hours, and no discoloration or dendrite was observed in the pattern, which was very good. There was no warpage at 0 mm. Sliding and bending was observed at 18 million times and was very good. Flame retardancy (photosensitive resin composition etc.) was equivalent to VTM-0.
Moreover, according to the measuring method of hardening temperature, when the crosscut peel after high-humidity processing was measured, all 100 pieces remained and it was a pass. Therefore, it was confirmed that the resin was completely cured at a curing temperature of 180 ° C.

(Example 5)
<Adjustment of photosensitive resin composition>
The polyimide precursor was synthesized in the same manner as in Example 1 except that the phosphorus flame retardant as component (D) was changed to 15 parts by weight of CR-733 manufactured by Daihachi Chemical Co., Ltd., and a photosensitive resin composition was prepared. .

<Evaluation of photosensitive dry film resist after imidization>
All 100 cross-cut peels remained and passed. The solder heat resistance temperature was 280 ° C. As for the photosensitivity, a hole of 100 μmφ and a line / space of 100 μm / 100 μm were drawn, and the photosensitivity was good. The migration resistance showed a resistance of 10 ¹⁰ Ω or more even after 1000 hours, and no discoloration or dendrite was observed in the pattern, which was very good. Warpage was good at 1 mm. The sliding bending was very good as observed 10 million times. Flame retardancy (photosensitive resin composition etc.) was equivalent to VTM-0.

  Moreover, according to the measuring method of hardening temperature, when the crosscut peel after high-humidity processing was measured, all 100 pieces remained and it was a pass. Therefore, it was confirmed that the resin was completely cured at a curing temperature of 180 ° C.

  In the measurement section of the crosscut peel, a laminate is obtained by heating at 180 ° C. for 2 hours, but this temperature is lowered to 160 ° C., and a laminate is prepared. When 100 cross-cut peel measurements were made, all 100 pieces remained and passed. Therefore, it was confirmed that the resin was completely cured (imidized) at a low temperature of 160 ° C.

(Comparative Example 1)
<Synthesis of polyimide precursor>
In a 3 L separable flask, a stirrer, a reflux condenser, a dropping funnel and a nitrogen introducing tank were installed, and under a nitrogen atmosphere, 14.62 g (50 mmol) of 1,3-bis (3-aminophenoxy) benzene, 4,4′-diamino 10.0 g (50 mmol) of diphenyl ether and 83.5 g of NMP (manufactured by Wako Pure Chemical Industries, Ltd.) were charged into the flask, and then 31.02 g (100 mmol) of ODPA was added. Stirring was continued under a nitrogen atmosphere for 20 hours after the addition to obtain a polyimide precursor solution.

  When the molecular weight of the obtained polyimide precursor was measured, the weight average molecular weight was 100,000, the number average molecular weight was 37000, and the weight average molecular weight / number average molecular weight was 2.7.

  The Tg of the polyimide precursor that was converted to polyimide was 240 ° C.

<Adjustment of photosensitive resin composition>
A photosensitive resin composition was prepared in the same manner as in Example 1 except that the polyimide precursor was changed to that synthesized in this example.

<Evaluation of photosensitive dry film resist after imidization>
All 100 cross-cut peels remained and passed. The solder heat resistance temperature was 250 ° C. As for the photosensitivity, although a hole of 500 μmφ and a line / space of 500 μm / 500 μm were somehow drawn, the shape was not good and the photosensitivity was not good. The migration resistance was short-circuited after about 200 hours, and discoloration and dendrite were observed in the pattern. The warpage was large at 8 mm. The sliding bending was not good at breaking 800,000 times. Flame retardancy (photosensitive resin composition etc.) was equivalent to VTM-0.

Moreover, according to the measuring method of hardening temperature, when the crosscut peel after high-humidity processing was measured, more than half peeled off and it was unacceptable. Therefore, it was confirmed that the resin was not completely cured at a curing temperature of 180 ° C.
(Comparative Example 2)
<Synthesis of polyimide precursor>
In a 3 L separable flask, a stirrer, a reflux condenser, a dropping funnel, and a nitrogen introducing tank were installed, and under a nitrogen atmosphere, 36.84 g (100 mmol) of 4,4′-bis (3-aminophenoxy) biphenyl, NMP (Wako Pure Chemical Industries, Ltd.) 99.4 g (manufactured by Kogyo Co., Ltd.) was charged into the flask, and then 29.42 g (100 mmol) of s-BPDA was added. Stirring was continued under a nitrogen atmosphere for 20 hours after the addition to obtain a polyimide precursor solution.

  When the molecular weight of the obtained polyimide precursor was measured, the weight average molecular weight was 90000, the number average molecular weight was 32000, and the weight average molecular weight / number average molecular weight was 2.8.

  Tg of the polyimide precursor that was converted to polyimide was 230 ° C.

<Adjustment of photosensitive resin composition>
A photosensitive resin composition was prepared in the same manner as in Example 1 except that the polyimide precursor was changed to that synthesized in this example.

<Evaluation of photosensitive dry film resist after imidization>
All 100 cross-cut peels remained and passed. The solder heat resistance temperature was 260 ° C. As for the photosensitivity, although a hole of 500 μmφ and a line / space of 500 μm / 500 μm were somehow drawn, the shape was not good and the photosensitivity was not good. The migration resistance was short-circuited after about 200 hours, and discoloration and dendrite were observed in the pattern. The warpage was large at 25 mm. The sliding bending was not good at breaking 600,000 times. Flame retardancy (photosensitive resin composition etc.) was equivalent to VTM-0.

  Moreover, according to the measuring method of hardening temperature, when the crosscut peel after high-humidity processing was measured, more than half peeled off and it was unacceptable. Therefore, it was confirmed that the resin was not completely cured at a curing temperature of 180 ° C.

  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 mentioned above, the photosensitive resin composition concerning this invention contains the polyimide precursor of a specific structure, and the (meth) acryl compound which has a carbon-carbon double bond as a structural component, and is 180 degrees C or less. It is the photosensitive resin composition characterized by hardening | curing at the temperature of. Therefore, it can be cured at a lower temperature than conventional ones. In addition, it has low warpage, excellent flexibility, flexibility, electrical reliability, and photosensitivity, and has flame retardancy. Therefore, the photosensitive resin composition according to the present invention can be used in the field of producing various resin molded products represented by films and laminates containing photosensitive polyimide, including photosensitive dry film resists. . Furthermore, it can be widely applied to fields related to the manufacture of electronic components using such films and laminates.

It is a schematic diagram which shows the comb-shaped pattern (line / space = 25micrometer / 25micrometer) formed on a flexible copper-clad laminated board in the method of evaluating the migration resistance of an Example. It is a schematic diagram which shows the sliding bending pattern (line / space = 250 micrometers / 250 micrometers) formed on a flexible copper bonding laminated board in the method of evaluating the sliding bending of a present Example.

Claims (10)

A photosensitive resin comprising at least (A) a polyimide precursor (B) a (meth) acrylate compound having a carbon-carbon double bond (C) a photoinitiator and being cured at a temperature of 180 ° C. or lower. Composition. A photosensitive resin characterized by containing at least (A) a polyimide precursor (B) a (meth) acrylate compound having a carbon-carbon double bond (C) a photoreaction initiator and being cured at a temperature of 160 ° C. or lower. Composition.  3. The photosensitive property according to claim 1, wherein the polyimide precursor does not contain 10 mol% or more of an aromatic diamine containing a para bond in the total diamine, and Tg after being polyimideized is 200 ° C. or less. Resin composition.  The photosensitive resin composition according to any one of claims 1 to 3, further comprising a flame retardant as the component (D) in addition to the components (A) to (C). The polyimide precursor has the following general formula (1)

(Wherein R ¹ represents a tetravalent organic group and R ² represents an aromatic compound directly bonded at the meta position) and the general formula (2)

(In the formula, R ¹ represents a tetravalent organic group, R ³ represents the general formula (3) or the general formula (4), provided that R ^{4 in the} general formula (3) represents — (CH ₂ ) _n. R ⁵ is a methyl group or a phenyl group, the phenyl group content in R ⁵ is 15 to 40%, m is a number of 4 to 20, and n is an integer of 2 to 5. In the general formula (4), R ⁶ represents H, a methyl group, an ethyl group, or a butyl group, r represents an integer of 1 to 20, and s represents an integer of 0 to 10). The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is contained.

In the general formula (1), the aromatic compound directly bonded at the meta position of R ² is m-phenylenediamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminophenyl ether, 3,3′-. Diaminophenyl sulfide, 3,3′-diaminophenylsulfone, 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) benze And a structure excluding the amino group of at least one compound selected from the group consisting of bis [4- (3-aminophenoxy) phenyl] sulfone and 2,2-bis (3-aminophenyl) propane. The photosensitive resin composition according to claim 5.   A photosensitive dry film resist obtained from the photosensitive resin composition according to claim 1.   A printed wiring board comprising the photosensitive dry film resist according to claim 7 as an insulating protective layer.  A method for producing a printed wiring board, wherein the photosensitive dry film resist according to claim 7 is cured at a temperature of 180 ° C. or less to form an insulating protective layer.  A method for producing a printed wiring board, comprising: curing the photosensitive dry film resist according to claim 7 at a temperature of 160 ° C. or less to form an insulating protective layer.

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