JP5662758B2 - Photosensitive resin laminate - Google Patents

Description

  The present invention relates to a photosensitive resin laminate and its use, and more specifically, a printed wiring board, a semiconductor package substrate such as BGA (Ball grid array) and CSP (Chip size package), a lead frame substrate, and a COF (Chip on film). The present invention relates to a photosensitive resin laminate suitable for the production of a wiring board for the like, a resist pattern forming method using the same, and a conductor pattern manufacturing method.

  Conventionally, as a resist for manufacturing printed circuit boards, semiconductor package substrates such as BGA and CSP, lead frame substrates, and COF circuit boards, a so-called dry film composed of a support film, a photosensitive resin layer, and a protective film is used. A film resist (hereinafter abbreviated as DFR) is used. The DFR is generally produced by laminating a photosensitive resin layer made of a photosensitive resin composition on a support film, and further laminating a protective film on the photosensitive resin layer. In order to form the photosensitive resin layer used here, it is a general practice to use an alkali developing type photosensitive resin composition that uses a weak alkaline aqueous solution as a developing solution.

  In addition, a transparent film that transmits active light is used as the support film. Examples of such a film include a polyvinyl alcohol film, a polycarbonate film, a polystyrene film, and a polyethylene terephthalate film. In general, a polyethylene terephthalate film having moderate flexibility and strength is used.

  Moreover, as a protective film, polyolefin films, such as a polyethylene film and a polypropylene film, and the polyester film surface-treated with silicone etc. may be used. A polyolefin film is generally used from the viewpoints of cost and peeling properties from the photosensitive resin layer (see Patent Documents 1 to 3).

  In order to fabricate a printed wiring board using DFR, first the protective film is peeled off, then a DFR is laminated on a permanent circuit creation board such as a copper clad laminated board or a flexible board, and a wiring pattern mask is obtained. The photosensitive resin layer is exposed through a film or the like. Next, if necessary, the support layer is peeled off, and the photosensitive resin layer in the unexposed part is dissolved or dispersed and removed by a developing solution to form a resist pattern on the substrate.

  After the resist pattern is formed (that is, after patterning), the process for forming a circuit is roughly divided into two methods. The first method is an etching method in which an exposed portion that is not covered with a resist pattern on a copper surface such as a copper clad laminate is removed by etching, and then the resist pattern portion is removed with an alkaline aqueous solution stronger than the developer. The second method appears by removing the resist pattern portion in the same manner after performing plating treatment of copper, solder, nickel, tin, or the like on the exposed portion of the copper surface as described above. This is a plating method for etching a copper surface such as a copper clad laminate. For etching, cupric chloride, ferric chloride, a copper ammonia complex solution, or the like is used.

  In the patterning process using DFR, the sensitivity of the photosensitive resin layer to actinic rays often becomes a problem from the viewpoint of productivity at the time of circuit formation. Further, DFR is usually provided as a roll-shaped photosensitive resin laminate having a three-layer structure of a support film, a photosensitive resin layer, and a protective film. There may be a problem that the sensitivity of the conductive resin layer is lowered. When such a roll-shaped DFR undergoes a hold time and the sensitivity is lowered, the resolution and adhesion of the resist pattern are lowered, causing a product defect.

  For this reason, in order to measure the sensitivity after the lapse of the hold time in the pre-shipment inspection of the photosensitive resin laminate, it is necessary to leave the photosensitive resin layer between coating and shipment. There was a problem with body productivity.

  In Patent Document 4, it is found that when the amount of the antioxidant contained in the protective film is 180 ppm or less and 0 ppm or more, a photosensitive resin laminate having high sensitivity and less sensitivity change (that is, sensitivity reduction) due to hold time can be obtained. ing.

Japanese Patent Laid-Open No. 08-123018 Japanese Patent Laid-Open No. 11-153861 JP 2002-323759 A Japanese Patent Application No. 2004-267497

  However, from the viewpoint of manufacturing a protective film, when a raw material having an antioxidant amount of 180 ppm or less is formed, the raw material is likely to be transformed by heat, so that it is necessary to form a film that suppresses heating and reduces the productivity of the protective film. There was a problem that there was.

  An object of the present invention is to provide a photosensitive resin laminate that has high sensitivity and excellent storage stability, and that can be shipped immediately after coating, so that productivity is good. Moreover, this invention includes the process of forming the photosensitive resin layer on a board | substrate using this photosensitive resin laminated body, the process of exposing this photosensitive resin layer, and the process of developing this photosensitive resin layer. Another object of the present invention is to provide a method for forming a resist pattern and a method for producing a conductor pattern, which have good adhesion to a substrate.

  As a result of studies to solve the above-mentioned problems, the present inventors have found that the sensitivity of the photosensitive resin layer in the photosensitive resin laminate immediately after formation, and after holding for 72 hours at a temperature of 23 ° C. and a relative humidity of 50%. It is possible to improve the productivity of the photosensitive resin laminate by the photosensitive resin laminate in which the sensitivity difference that is the difference from the sensitivity of the photosensitive resin layer in the photosensitive resin laminate is 3 or less in a 27-step tablet. Discovered and led to the present invention. That is, the present invention is as follows.

（式中、Ｒ₁及びＲ₂は各々独立に水素又は炭素数１〜６のアルキル基を示す。）
で表される構造を含む酸化防止剤を含有し、
該酸化防止剤のフェノール当量が３．１×１０^-3以下であり、
該保護フィルム中の該酸化防止剤の含有量が、１ｐｐｍより多く３０００ｐｐｍ以下である、［１］に記載の感光性樹脂積層体。
［３］ 該（Ｃ）保護フィルムがポリエチレンフィルムである、［１］又は［２］に記載の感光性樹脂積層体。
［４］ ［１］〜［３］のいずれかに記載の感光性樹脂積層体を用いてレジストパターンを形成する方法であって、
該保護フィルムを剥離しながら基板上に該感光性樹脂層をラミネートすることにより該基板上に該感光性樹脂層を形成するラミネート工程と、
該基板上に形成された該感光性樹脂層を露光する露光工程と、
該露光後の感光性樹脂層を現像することによって該基板上にレジストパターンを形成する現像工程と、
を含む、レジストパターンの形成方法。
［５］ ［１］〜［３］のいずれかに記載の感光性樹脂積層体を用いて導体パターンを製造する方法であって、
該保護フィルムを剥離しながら基板上に該感光性樹脂層をラミネートすることにより該基板上に該感光性樹脂層を形成するラミネート工程と、
該基板上に形成された該感光性樹脂層を露光する露光工程と、
該露光後の感光性樹脂層を現像することによって該基板上にレジストパターンを形成する現像工程と、
該レジストパターンが形成された基板をエッチング又はめっきする導体パターン形成工程と、
を含む、導体パターンの製造方法。 [1] A photosensitive resin laminate comprising at least (A) a support film, (B) a photosensitive resin layer made of a photosensitive resin composition, and (C) a protective film, wherein the (C) protective film Is laminated in contact with the photosensitive resin layer comprising the photosensitive resin composition (B),
The difference between the sensitivity of the photosensitive resin layer in the photosensitive resin laminate immediately after formation and the sensitivity of the photosensitive resin layer in the photosensitive resin laminate after holding for 72 hours at a temperature of 23 ° C. and a relative humidity of 50% after formation. A certain sensitivity difference is 3 steps or less in a 27 step tablet,
The sensitivity is such that the photosensitive resin layer is exposed with an exposure amount of 13 steps for a 27-step tablet, and then developed with a 1% by mass aqueous sodium carbonate solution at 30 ° C. for a time period twice the minimum development time. The photosensitive resin laminated body represented as the maximum number of remaining film steps of the cured resist obtained by this.
[2] The protective film (C) has the following general formula (I):

(In the formula, R ₁ and R ₂ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.)
Containing an antioxidant containing a structure represented by
The phenol equivalent of the antioxidant is 3.1 × 10 ⁻³ or less,
The photosensitive resin laminate according to [1], wherein the content of the antioxidant in the protective film is more than 1 ppm and not more than 3000 ppm.
[3] The photosensitive resin laminate according to [1] or [2], wherein the protective film (C) is a polyethylene film.
[4] A method of forming a resist pattern using the photosensitive resin laminate according to any one of [1] to [3],
A laminating step of forming the photosensitive resin layer on the substrate by laminating the photosensitive resin layer on the substrate while peeling off the protective film;
An exposure step of exposing the photosensitive resin layer formed on the substrate;
A development step of forming a resist pattern on the substrate by developing the photosensitive resin layer after the exposure;
A method for forming a resist pattern, comprising:
[5] A method for producing a conductor pattern using the photosensitive resin laminate according to any one of [1] to [3],
A laminating step of forming the photosensitive resin layer on the substrate by laminating the photosensitive resin layer on the substrate while peeling off the protective film;
An exposure step of exposing the photosensitive resin layer formed on the substrate;
A development step of forming a resist pattern on the substrate by developing the photosensitive resin layer after the exposure;
A conductor pattern forming step of etching or plating the substrate on which the resist pattern is formed;
The manufacturing method of a conductor pattern containing this.

  ADVANTAGE OF THE INVENTION According to this invention, the photosensitive resin laminated body with favorable productivity can be provided by being highly sensitive and excellent in storage stability, and being able to ship immediately after coating. Furthermore, according to the present invention, the photosensitive resin laminate is used to form a photosensitive resin layer on the substrate, and the adhesiveness to the substrate is good, including exposing and developing the photosensitive resin layer. It is possible to provide a method of forming a resist pattern and a method of manufacturing a conductor pattern.

  Hereinafter, the present invention will be specifically described.

<Photosensitive resin laminate>
In one embodiment, the present invention provides (A) a support film, (B) a photosensitive resin layer comprising a photosensitive resin composition (hereinafter also referred to as (B) a photosensitive resin layer), and (C) protection. A photosensitive resin laminate comprising at least a film, wherein the protective film (C) is laminated in contact with the photosensitive resin layer comprising the photosensitive resin composition (B), Sensitivity of the photosensitive resin layer in the laminate, and sensitivity of the photosensitive resin layer in the photosensitive resin laminate after holding for 72 hours at a temperature of 23 ° C. and a relative humidity of 50% (hereinafter also referred to as hold time sensitivity). The difference in sensitivity is 3 steps or less with a 27-step tablet, and the sensitivity is such that the photosensitive resin layer is exposed with an exposure amount of 13 steps for the 27-step tablet, and then 1% by mass at 30 ° C. Sodium carbonate water Expressed as the highest residual film stages of curing the resist obtained by development over twice the time duration of the minimum developing time by using a liquid, to provide a photosensitive resin laminate. Such a photosensitive resin laminate is highly sensitive because there is little decrease in sensitivity after coating of the photosensitive resin layer, and has good productivity because it can be shipped immediately after coating. Further, by using such a photosensitive resin laminate, it is possible to form a resist pattern and a conductor pattern with good adhesion to the substrate. In the present invention, the sensitivity difference defined as described above may be 3 steps or less, but from the viewpoint of storage stability, it is preferably 2 steps or less, more preferably 1 step or less.

  In addition, the sensitivity difference described in this specification is 72 at a temperature of 23 ° C. and a relative humidity of 50% after the formation of the photosensitive resin laminate immediately after the formation (essentially immediately after the formation (coating) of the photosensitive resin layer). It means the difference in sensitivity measured using the photosensitive resin laminate after holding for a time. In the measurement of sensitivity, the photosensitive resin laminate is laminated, for example, on a copper-clad laminate while peeling off the protective film, and the sensitivity of the photosensitive resin layer is measured using the obtained laminate. Specifically, the photosensitive resin layer is exposed through a 27-step step tablet with an exposure amount that makes the 27-step step tablet 13 steps, and then a minimum development time of 2 using a 1% by mass aqueous sodium carbonate solution at 30 ° C. The sensitivity is defined as the maximum number of remaining film stages of the cured resist obtained by developing over a double time period. The minimum development time is the minimum time required for developing and removing the uncured portion of the photosensitive resin layer, and the maximum remaining film step number is the highest step number at which the remaining film of the cured resist can be seen in the step tablet. is there. The 27-step tablet used here is a 27-step tablet made by Stofer, in which rectangular masks of various densities are arranged, and the optical density is increased by 0.05 per step, The number of steps of the step tablet, the optical density, and the light transmittance have a relationship as shown in Table 3 to be described later.

  The photosensitive resin laminate of the present invention is typically a laminate in which a support film, a photosensitive resin layer, and a protective film are laminated in this order. The photosensitive resin laminate of the present invention typically comprises a support film, a photosensitive resin layer, and a protective film. For example, the photosensitive resin laminate has a photosensitive property between the photosensitive resin layer and the support film. It may further have one or more developable resin layers that do not have.

[(A) Support film]
The support film used in the photosensitive resin laminate of the present invention may be any film as long as it functions as a support for the photosensitive resin, but preferably has high smoothness and is transmissive to actinic rays used for exposure. Is a high organic polymer film.

  The haze of the support film is preferably 5.0 or less, more preferably 3.0 or less, and even more preferably 1.0 or less. When the haze is 5.0 or less, the actinic ray transmittance is good. The haze is a value measured with a haze meter (for example, HAZE METER NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.).

  The thickness of the support film is preferably 5 to 25 μm, particularly preferably 9 to 16 μm. The thickness is preferably 5 μm or more from the viewpoint of maintaining strength as a support film, and is 25 μm or less from the viewpoint of maintaining good resolution of the photosensitive resin layer in order to produce fine wiring. It is preferable. The thickness described in the present specification is a value measured with a micrometer (for example, a Digimatic standard outer micrometer MDE-MJ manufactured by Mitutoyo Corporation).

  Examples of preferred support films include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyvinyl alcohol, polyvinyl chloride, vinyl chloride copolymer, polyvinylidene chloride, vinylidene chloride copolymer, polymethyl methacrylate copolymer. , Films of polystyrene, polyacrylonitrile, styrene copolymers, polyamide, cellulose derivatives and the like. Preferably, polyethylene terephthalate is used.

[(C) Protective film]
The protective film is laminated in contact with the photosensitive resin layer (B) described in detail later. As the protective film, a film having high smoothness and lower adhesion to the photosensitive resin layer than the support film is used. The protective film is typically an organic polymer film.

  The thickness of the protective film is preferably 10 to 60 μm, particularly preferably 15 to 50 μm. The thickness is preferably 10 μm or more from the viewpoint of maintaining the smoothness of the protective film itself, and preferably 60 μm or less from the viewpoint of maintaining the operability as a film constituting the photosensitive resin laminate.

  Preferable examples of the protective film include films such as polyolefins such as polyethylene and polypropylene; polyesters or polyesters whose peelability is improved by silicone treatment or alkyd treatment; A polyolefin film is generally used, and a polyethylene film is preferably used from the viewpoint of handling properties and cost.

  Among the above, the polyolefin film can be obtained by forming a film by extruding a polyolefin resin by an inflation molding method, a cast film molding method using a T-die, or the like, followed by stretching treatment.

（式中、Ｒ₁及びＲ₂は各々独立に水素又は炭素数１〜６のアルキル基を示す。）
で表される構造を含み且つフェノール当量が３．１×１０^-3以下である酸化防止剤（以下、単に酸化防止剤ということもある）を含有することが好ましい。このような酸化防止剤を使用することは、形成直後の感光性樹脂積層体における感光性樹脂層の感度と、形成後に温度２３℃及び相対湿度５０％で７２時間保持した後の感光性樹脂積層体における感光性樹脂層の感度との差を、２７段ステップタブレットで３段以下にするために有効な手段である。 In the present invention, the protective film (C) has the following general formula (I):

(In the formula, R ₁ and R ₂ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.)
It is preferable to contain an antioxidant having a structure represented by the formula (II) and having a phenol equivalent of 3.1 × 10 ⁻³ or less (hereinafter sometimes simply referred to as an antioxidant). The use of such an antioxidant means that the sensitivity of the photosensitive resin layer in the photosensitive resin laminate immediately after formation, and the photosensitive resin laminate after holding for 72 hours at a temperature of 23 ° C. and a relative humidity of 50% after formation. This is an effective means for making the difference from the sensitivity of the photosensitive resin layer in the body 3 or less with a 27-step tablet.

In the case of producing a photosensitive resin laminate in which a photosensitive resin layer and a protective film are laminated (typically laminated in contact with each other), the present inventors present an oxidation present in the protective film. It was thought that the inhibitor may flow out (bleed) with time after the production of the photosensitive resin laminate and partially transfer to the photosensitive resin layer. It can be understood that, due to this shift, the antioxidant inhibits radical polymerization in the photosensitive resin layer during exposure, and the photosensitive resin layer does not exhibit sufficient sensitivity as a resist. Further, it can be understood that when the photosensitive resin laminate is stored in a roll shape, the amount of bleed of the antioxidant increases with time, and the sensitivity decreases. Therefore, in order to obtain a photosensitive resin laminate having sufficient sensitivity and less sensitivity change (ie, sensitivity reduction) due to hold time, it is difficult to transfer the antioxidant contained in the protective film to the photosensitive resin layer. is necessary. The present inventors have added an antioxidant containing a structure represented by the above general formula (I) and having a phenol equivalent of 3.1 × 10 ⁻³ or less to the protective film, thereby providing an antioxidant. It has been found that bleed can be prevented. The use of the above-mentioned antioxidant is an effective means for obtaining the photosensitive resin laminate of the present invention with little decrease in sensitivity over time, and thereby increasing the productivity of the photosensitive resin laminate.

The phenol equivalent of the antioxidant used in a preferred embodiment of the present invention is preferably 3.1 × 10 ⁻³ or less, more preferably 2.0 × 10 6 from the viewpoint of preventing the antioxidant from flowing out (bleed). ^-3 or less. In addition, the lower limit of the phenol equivalent is preferably 4.0 × 10 ⁻⁴ or more, more preferably 1.0 × 10 ⁻³ or more, and more preferably 1.5 × from the viewpoint of efficacy and dispersibility as an antioxidant. 10 ⁻³ or more is most preferable. Examples of the antioxidant having a phenol equivalent within the above range include compounds having a long alkyl chain, and the compound is particularly advantageous in terms of preventing the antioxidant from flowing out (bleed).

  The phenol equivalent here means a value obtained by dividing the number of structures represented by the above general formula (I) (that is, a phenyl group or an alkyl-substituted phenyl group) by the molecular weight of the antioxidant. The reason why the bleeding of the antioxidant can be prevented by setting the phenol equivalent within the predetermined range of the present invention is that the antioxidant contains a long alkyl chain, so that the constituent polymer of the antioxidant and the protective film ( For example, the affinity with polyolefin) is improved, or the migration rate of the antioxidant to the photosensitive resin layer is extremely decreased due to the bulkiness of the long alkyl chain, or both of them occur simultaneously. It is possible. In calculating the phenol equivalent, the number of structures represented by the above general formula (I) is calculated based on the absorbance at 550 nm using the fact that phenol reacts with 4-nitroaniline and nitrous acid to develop color. The molecular weight of the antioxidant is confirmed by, for example, a gas chromatograph mass spectrometer (GC-MS).

  A particularly preferred example of the structure represented by the general formula (I) is 3,5-di-tert-butyl-4-hydroxyphenyl.

  Preferable examples of the antioxidant used in the present invention include Irganox 1076, Irganox 1135, Irganox 565 and Irganox 259 (hereinafter referred to as Specialty Chemicals), and Sumilizer GP and Sumilizer GS.

（式中、Ｒ₁及びＲ₂は各々独立に水素又は炭素数１〜６のアルキル基を示し、Ｒ₃は炭素数１０〜３０のアルキル基を示す。）
で表される化合物であることが、ホールドタイムによる感度低下抑制の観点から好ましい。Ｒ₃の炭素数は、より好ましくは、１５〜２５である。 The antioxidant used in a preferred embodiment of the present invention is represented by the following general formula (II):

(In the formula, R ₁ and R ₂ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and R ₃ represents an alkyl group having 10 to 30 carbon atoms.)
It is preferable from a viewpoint of the sensitivity fall suppression by hold time. The number of carbon atoms in R ₃ is more preferably 15-25.

  The content of the antioxidant in the protective film is preferably more than 1 ppm, more preferably more than 180 ppm. When the content is more than 1 ppm, raw material modification due to heat is less likely to occur, so that the protective film can be produced with high productivity without lowering the heating temperature and stirring force in the polymer kneading step during the formation of the protective film. The content is more preferably 300 ppm or more, still more preferably 400 ppm or more. The upper limit of the content of the antioxidant in the protective film is preferably 3000 ppm or less, more preferably 2000 ppm or less, and even more preferably 1000 ppm or less from the viewpoint of preventing sensitivity change of the photosensitive resin.

  The content of the antioxidant in the protective film is controlled by, for example, controlling the amount of the antioxidant added to the constituent polymer (for example, polyolefin resin) of the protective film during the production of the protective film. The content of the antioxidant in the protective film is a value converted from the charged amount. In addition, the said content of the antioxidant in a protective film can also be confirmed directly by GC-MS method, for example.

In the present invention, it is preferably represented by the above general formula (I) as long as it does not inhibit the effect of the antioxidant that a high-sensitivity photosensitive resin laminate is obtained with little reduction in sensitivity due to hold time. In addition to the antioxidant containing the structure and having a phenol equivalent of 3.1 × 10 ⁻³ or less, other types of additional antioxidants can be used in combination as appropriate. Additional antioxidants that can be used include, for example:

  2,6-di-tert-butyl-4-methylphenol, alkylated phenol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol), 4,4′-butylidenebis- (6-t -Butyl-3-methylphenol), 2,2'-methylenebis- (4-methyl-6-t-butylphenol), 2,2'-methylenebis- (4-ethyl-6-t-butylphenol), 2,6 -Di-t-butyl-4-ethylphenol, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, tetrakis [methylene-3- (3,5-di- t-butyl-4-hydroxyphenyl) propionate] methane, dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiopropionate.

  Also, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3, 5-di-t-butylanilino) -1,3,5-triazine, pentaerythritol-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylene Bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 3 , 5-Di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di- -Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl] -O -Cresol etc. are also mentioned.

  Moreover, N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine or the like can be used as a hydrazine antioxidant. In addition, conventionally known phenolic antioxidants, phosphite antioxidants, thioether antioxidants, heavy metal deactivators, and the like can be applied.

  As described above, it is preferable that the additional antioxidant contained in the protective film is effective during molding of the protective film and does not inhibit the photoradical polymerization of the photosensitive resin composition. A suitable content of the additional antioxidant in the protective film is 180 ppm or less.

  On the other hand, high sensitivity of the photosensitive resin layer can be achieved from an approach based on the type and blending amount of the photopolymerization initiator in the photosensitive resin composition, but for example, the blending amount of the photopolymerization initiator is increased. As a result, the amount of scum in the developer increases and the storage stability also deteriorates. From the viewpoint of suppressing the change in sensitivity due to the hold time, it is extremely useful to use a specific protective film using an antioxidant that does not easily migrate to the photosensitive resin layer as the material of the photosensitive resin laminate.

  The protective film may further contain an antistatic agent, a lubricant, an antiblocking agent, a filler and the like as an additive in addition to the preferred antioxidant used in the present invention and the additional antioxidant described above. These additives can be contained in the protective film, for example, by appropriately mixing in the raw material when the protective film is produced.

[(B) Photosensitive resin layer]
The photosensitive resin layer is a layer made of a photosensitive resin composition. As the photosensitive resin composition, preferably, (a) the acid equivalent of the carboxyl group is 100 to 600 and the weight average molecular weight is 5000 to 500,000 (hereinafter also referred to as (a) binder resin). ), (B) a photopolymerizable unsaturated compound, and (c) a photopolymerization initiator. The above composition is advantageous in terms of resist pattern forming performance.

((A) Binder resin)
(A) It is preferable that resin for binders contains a carboxyl group in the quantity from which the acid equivalent of a carboxyl group will be 100-600. The acid equivalent of the carboxyl group is more preferably 300 to 400. The acid equivalent of a carboxyl group described in this specification means the mass (gram) of a resin (for example, a linear polymer) having one equivalent of a carboxyl group therein. (A) The carboxyl group in the binder resin is necessary for giving the photosensitive resin layer developability and releasability with respect to an aqueous alkali solution. The acid equivalent is preferably 100 or more from the viewpoint of development resistance, resolution, and adhesion, and is preferably 600 or less from the viewpoint of developability and peelability.

  (A) It is preferable that the weight average molecular weight of resin for binders is 5000-500000. The weight average molecular weight is more preferably 10,000 to 200,000. (A) The weight average molecular weight of the resin for binder is preferably 500,000 or less from the viewpoint of resolution, and is preferably 5,000 or more from the viewpoint of edge fuse.

  The acid equivalent is measured by potentiometric titration using an automatic titrator (for example, Hiranuma Auto titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd.) using 0.1 mol / L sodium hydroxide. The

  The weight average molecular weight is determined by gel permeation chromatography (for example, gel permeation chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 type, column: Shodex manufactured by Showa Denko KK). (Trademark) (KF-807, KF-806M, KF-806M, KF-802.5) in series, moving bed solvent: tetrahydrofuran, using calibration curve with polystyrene standard sample)) It is done.

  (A) The binder resin can be typically obtained by polymerization of the following first monomer or copolymerization of the following first monomer and second monomer. Each of the first monomer and the second monomer can be used alone or in combination of two or more.

  The first monomer is a carboxylic acid or carboxylic anhydride having one polymerizable unsaturated group in the molecule. Examples include (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, maleic acid half ester, and the like.

  The second monomer is non-acidic, has one polymerizable unsaturated group in the molecule, develops the photosensitive resin layer, resists etching and plating, and cures the photosensitive resin layer. The cured film thus formed is selected so as to retain various properties such as flexibility. Examples of the second monomer include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate, and 2-hydroxyethyl (meth) ) Acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylonitrile and the like. Moreover, the vinyl compound (for example, styrene) which has a phenyl group is preferable at the point of high resolution.

  (A) The binder resin is prepared by diluting the above monomers (one or a mixture of two or more) with a solvent such as acetone, methyl ethyl ketone, or isopropanol, and adding benzoyl peroxide or azoisobutyro It is preferable to synthesize by adding an appropriate amount of a radical polymerization initiator such as nitrile and stirring with heating. In some cases, the synthesis is performed while a part of the mixture is dropped into the reaction solution. After completion of the reaction, a solvent may be further added to adjust to a desired concentration. As a synthesis means, in addition to the above solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization may be used.

  Content of (a) binder resin in the photosensitive resin composition becomes like this. Preferably it is 20-90 mass%, More preferably, it is 30-70 mass%. From the viewpoint that the resist pattern formed by exposure and development has sufficient resist properties, such as tenting, etching, and various plating processes, the content is 20 to 90% by mass. Is preferred.

((B) Photopolymerizable unsaturated compound)
(B) As the photopolymerizable unsaturated compound, a compound having a photopolymerizable unsaturated group such as a (meth) acryl group can be preferably used. Examples of the (b) photopolymerizable unsaturated compound that can be used include 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and polyethylene glycol. Di (meth) acrylate, 2-di (p-hydroxyphenyl) propane di (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyoxypropyltrimethylolpropane tri (meth) acrylate, poly Oxyethyltrimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane triglycidyl ester Tertri (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, β-hydroxypropyl-β ′-(acryloyloxy) propyl phthalate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate , Nonylphenoxy polyalkylene glycol (meth) acrylate, polypropylene glycol mono (meth) acrylate and the like.

  In addition, examples of the (b) photopolymerizable unsaturated compound include urethane compounds having a (meth) acryl group. Examples of the urethane compound include diisocyanate compounds such as hexamethylene diisocyanate, tolylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate, and compounds having a hydroxyl group and a (meth) acryl group in one molecule (for example, 2-hydroxypropyl acrylate, oligopropylene glycol monomethacrylate and the like) and the like. Specifically, there is a reaction product of hexamethylene diisocyanate and oligopropylene glycol monomethacrylate (Nippon Yushi Co., Ltd., Bremma-PP1000).

（式中、Ｒ₄及びＲ₅は各々独立に水素又はＣＨ₃を示し、ｎ₁、ｎ₂及びｎ₃は各々独立に３〜２０の整数を示す。）
又は下記一般式（ＩＶ）：

（式中、Ｒ₆及びＲ₇は各々独立に水素又はＣＨ₃を示し、ＡはＣ₂Ｈ₄を示し、ＢはＣＨ₂ＣＨ（ＣＨ₃）を示し、ｎ₄＋ｎ₅は２〜３０の整数を示し、ｎ₆＋ｎ₇は０〜３０の整数を示し、ｎ₄及びｎ₅は各々独立に１〜２９の整数を示し、ｎ₆及びｎ₇は各々独立に０〜２９の整数を示す。−（Ａ−Ｏ）−及び−（Ｂ−Ｏ）−の繰り返し単位の配列は、ランダムであってもブロックであってもよく、ブロックの場合、−（Ａ−Ｏ）−及び−（Ｂ−Ｏ）−の順序は、何れがビスフェニル基側であってもよい。）
で表される化合物であることが好ましい。このような化合物は、ＤＦＲのホールドタイムによる感度低下が少ないという観点から好ましい。また、上記一般式（ＩＩＩ）又は（ＩＶ）で表される化合物を２種以上併用してもよく、さらに、１種以上のこれらの化合物と、前述した他の光重合性不飽和化合物とを併用してもよい。 In addition, (b) the photopolymerizable unsaturated compound has the following general formula (III):

(In the formula, R ₄ and R ₅ each independently represent hydrogen or CH ₃ , and n ₁ , n ₂ and n ₃ each independently represents an integer of 3 to 20)
Or the following general formula (IV):

(Wherein R ₆ and R ₇ each independently represent hydrogen or CH ₃ , A represents C ₂ H ₄ , B represents CH ₂ CH (CH ₃ ), and n ₄ + n ₅ represents 2-30. N ₆ + n ₇ represents an integer of 0 to 30, n ₄ and n ₅ each independently represents an integer of 1 to 29, and n ₆ and n ₇ each independently represents an integer of 0 to 29. The arrangement of repeating units of-(A-O)-and-(B-O)-may be random or block, and in the case of a block,-(A-O)-and-(B Any order of -O)-may be on the bisphenyl group side.
It is preferable that it is a compound represented by these. Such a compound is preferable from the viewpoint that the decrease in sensitivity due to the DFR hold time is small. In addition, two or more compounds represented by the general formula (III) or (IV) may be used in combination, and one or more of these compounds and the other photopolymerizable unsaturated compound described above may be used. You may use together.

In the compound represented by the general formula (III), it is preferable that n ₁ , n ₂ and n ₃ are each independently 3 or more from the viewpoint of boiling point and odor. From the viewpoint of sensitivity due to the concentration of the photoactive site per unit mass, it is preferable that n ₁ , n ₂ and n ₃ are each independently 20 or less.

  Specific examples of the compound represented by the general formula (III) include, for example, a glycol dimethacrylate in which an average of 12 moles of propylene oxide is added to polypropylene glycol and an average of 3 moles of ethylene oxide is added to both ends. As mentioned.

In the compound represented by the general formula (IV), n ₄ + n ₅ and n ₆ + n ₇ are each preferably 30 or less from the viewpoint of sensitivity.

  Specific examples of the compound represented by the general formula (IV) include polyalkylene glycol dimethacrylate and bisphenol A each having an average of 2 moles of propylene oxide and an average of 6 moles of ethylene oxide added to both ends of bisphenol A. Polyethylene glycol dimethacrylate (NK ester BPE-500 manufactured by Shin-Nakamura Chemical Co., Ltd.) with an average of 5 moles of ethylene oxide added to both ends, and an average of 2 moles of ethylene oxide to both ends of bisphenol A, respectively. Examples include polyethylene glycol dimethacrylate (NK Nakamura Chemical Co., Ltd. NK ester BPE-200).

  The content of (b) the photopolymerizable unsaturated compound in the photosensitive resin composition is preferably in the range of 3 to 70% by mass. The content is preferably 3% by mass or more from the viewpoint of sensitivity, and preferably 70% by mass or less from the viewpoint of edge fuse. The content is more preferably 10 to 60% by mass, still more preferably 15 to 55% by mass.

（式中、Ｘ、Ｙ及びＺは各々独立に水素、アルキル基、アルコキシ基又はハロゲン基を示し、ｐ、ｑ及びｒは各々独立に１〜５の整数を示す。）
で表される２，４，５−トリアリールイミダゾール二量体を含むことが、高感度の観点から好ましい。 ((C) Photopolymerization initiator)
(C) As a photoinitiator, the photoinitiator generally used in the synthesis | combination of a photopolymerizable resin can be used. (C) The photopolymerization initiator has the following general formula (V):

(In the formula, X, Y and Z each independently represent hydrogen, an alkyl group, an alkoxy group or a halogen group, and p, q and r each independently represent an integer of 1 to 5.)
It is preferable from a highly sensitive viewpoint that the 2,4,5- triaryl imidazole dimer represented by these is included.

  In the compound represented by the general formula (V), the covalent bond that binds two lophine groups is 1,1′-, 1,2′-, 1,4′-, 2,2′-, Although it is in the 2,4′- or 4,4′-position, a compound in the 1,2′-position is preferred from the viewpoint of ease of synthesis.

  Examples of the 2,4,5-triarylimidazole dimer include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-bis- (M-methoxyphenyl) imidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer and the like can be mentioned, and in particular, 2- (o-chlorophenyl) -4,5- A diphenylimidazole dimer is preferred from the viewpoint of storage stability.

  (C) As a photopolymerization initiator, the 2,4,5-triarylimidazole dimer represented by the general formula (V) and p-aminophenylketone are used in combination as a photosensitive resin composition. From the viewpoint of sensitivity, resolution, and adhesion. Examples of p-aminophenyl ketone include p-aminobenzophenone, p-butylaminophenone, p-dimethylaminoacetophenone, p-dimethylaminobenzophenone, p, p'-bis (ethylamino) benzophenone, p, p'- Examples thereof include bis (dimethylamino) benzophenone [Michler's ketone], p, p′-bis (diethylamino) benzophenone, p, p′-bis (dibutylamino) benzophenone, and the like.

  Moreover, as (c) photoinitiator, it is also possible to use other photoinitiators other than the compound shown above. As the other photopolymerization initiator, any compound that is activated by various actinic rays, for example, ultraviolet rays and the like, and initiates polymerization of the resin raw material can be used.

  Other photopolymerization initiators include, for example, quinones such as 2-ethylanthraquinone and 2-tert-butylanthraquinone; aromatic ketones such as benzophenone; benzoin ethers such as benzoin, benzoin methyl ether and benzoin ethyl ether; Acridine compounds such as 9-phenylacridine; ketals such as benzyldimethyl ketal and benzyldiethyl ketal;

  Moreover, for example, combinations of thioxanthones such as thioxanthone, 2,4-diethylthioxanthone, and 2-chlorothioxanthone and tertiary amine compounds such as dimethylaminobenzoic acid alkyl ester compounds are also included.

  Further, oxime esters such as 1-phenyl-1,2-propanedione-2-O-benzoyloxime and 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) oxime are also included. It is also possible to use N-aryl-α-amino acid compounds. Among these, N-phenylglycine is particularly preferable.

  Further, pyrazoline compounds, acridone compounds, coumarin compounds, anthracene compounds and the like may be used.

  Examples of the pyrazoline compound include 1- (4-tert-butyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1-phenyl-3- (4-tert-butyl-styryl) -5- (4-tert -Butyl-phenyl) -pyrazoline, 1,5-bis- (4-tert-butyl-phenyl) -3- (4-tert-butyl-styryl) -pyrazoline, 1- (4-tert-octyl-phenyl)- 3-styryl-5-phenyl-pyrazoline, 1-phenyl-3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline, 1,5-bis- (4-tert -Octyl-phenyl) -3- (4-tert-octyl-styryl) -pyrazoline, 1- (4-dodecyl-phenyl) -3-styryl-5-fur Nyl-pyrazoline, 1-phenyl-3- (4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-dodecyl-stynyl)- 5- (4-dodecyl-phenyl) -pyrazoline, 1- (4-tert-octyl-phenyl) -3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline, 1- (4-tert-butyl-phenyl) -3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline, 1- (4-tert-butyl-phenyl) -3- (4-dode Ru-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -Pyrazolin, 1- (4-tert-octyl-phenyl) -3- (4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (2,4-dibutyl-phenyl) -3 -(4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1-phenyl-3- (3,5-di-tert-butyl-styryl) -5- (3,5-di- tert-butyl-phenyl) -pyrazoline, 1-phenyl-3- (2,6-di-tert-butyl-styryl) -5- (2,6-di-tert-butyl-phenyl) -pyrazoline, Phenyl-3- (2,5-di-tert-butyl-styryl) -5- (2,5-di-tert-butyl-phenyl) -pyrazoline, 1-phenyl-3- (2,6-di-n -Butyl-styryl) -5- (2,6-di-n-butyl-phenyl) -pyrazoline, 1- (3,4-di-tert-butyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1- (3,5-di-tert-butyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1- (4-tert-butyl-phenyl) -3- (3,5-di-tert-butyl -Phenyl) -pyrazolin, 1- (3,5-di-tert-butyl-phenyl) -3- (3,5-di-tert-butyl-styryl) -5- (3,5-di-tert-butyl) -Phenyl) -pyrazoline It is. Of these, 1-phenyl-3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline is preferable.

  Examples of the acridone compounds include acridone, chloroacridone, N-methylacridone, N-butylacridone, N-butyl-chloroacridone, 2-chloro-10-butylacridone, 10-N-butyl-2- And chloroacridone.

  Coumarin compounds include coumarin, 7-amino-4-methylcoumarin, 7-dimethylamino-4-methylcoumarin, 7-diethylamino-4-methylcoumarin, 7-methylamino-4-methylcoumarin, and 7-ethylamino. -4-methylcoumarin, 7-dimethylaminocyclopenta [c] coumarin, 7-aminocyclopenta [c] coumarin, 7-diethylaminocyclopenta [c] coumarin, 4,6-dimethyl-7-ethylaminocoumarin, 4 , 6-Diethyl-7-ethylaminocoumarin, 4,6-dimethyl-7-diethylaminocoumarin, 4,6-dimethyl-7-dimethylaminocoumarin, 4,6-diethyl-7-diethylaminocoumarin, 4,6-diethyl -7-dimethylaminocoumarin, 4,6-dimethyl-7-ethylaminocoumarin 3- (2-benzofuroyl) -7-diethylaminocoumarin, 3- (2-benzofuroyl) -7- (1-pyrrolidinyl) coumarin, 3-benzoyl-7-diethylaminocoumarin, 3- (2-methoxybenzoyl) -7 -Diethylaminocoumarin, 3- (4-dimethylaminobenzoyl) -7-diethylaminocoumarin, 3,3'-carbonylbis (5,7-di-n-propoxycoumarin), 3,3'-carbonylbis (7-diethylamino) Coumarin), 3-benzoyl-7-methoxycoumarin, 3- (2-furoyl) -7-diethylaminocoumarin, 3- (4-diethylaminocinnamoyl) -7-diethylaminocoumarin, 7-methoxy-3- (3-pyridyl) Carbonyl) coumarin, 3-benzoyl-5,7-dipropoxycoumarin And the like.

  Anthracene compounds include anthracene, 9-methylanthracene, 9-ethylanthracene, 9-propylanthracene, 9-butylanthracene, 9,10 dimethylanthracene, 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 9, Examples include 10-diphenylanthracene, 9,10-dialkoxyanthracene-2-carboxylic acid compound (described in JP-A-2008-1000097).

  The content of the photopolymerization initiator (c) in the photosensitive resin composition is preferably 0.1 to 20% by mass, more preferably 1 to 10% by mass. When the content is less than 0.1% by mass, the sensitivity tends to be low. On the other hand, when the content exceeds 20% by mass, fogging of the photosensitive resin layer is likely to occur due to diffraction of light through a photomask during exposure, and as a result, resolution tends to be low.

  The photosensitive resin composition can contain coloring substances such as dyes and pigments. Examples of coloring substances that can be used include fuchsin, phthalocyanine green, auramin base, chalcoxide green S, paramadienta, crystal violet, methyl orange, nile blue 2B, Victoria blue, malachite green (manufactured by Hodogaya Chemical Co., Ltd., Eisen (registered trademark) ) MALACHITE GREEN), basic blue 20, diamond green (Eisen (registered trademark) DIAMOND GREEN GH manufactured by Hodogaya Chemical Co., Ltd.) and the like.

  The photosensitive resin composition can contain a coloring dye that develops color when irradiated with light. Examples of the coloring dye that can be used include a combination of a leuco dye or a fluorane dye and a halogen compound.

  Examples of the leuco dye include tris (4-dimethylamino-2-methylphenyl) methane [leuco crystal violet], tris (4-dimethylamino-2-methylphenyl) methane [leucomalachite green], and the like. .

  Examples of the halogen compound include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris (2, 3 -Dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane, hexachloroethane, triazine compounds and the like.

  Examples of the triazine compound include 2,4,6-tris (trichloromethyl) -s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine and the like.

  Among such color developing dyes, a combination of tribromomethylphenylsulfone and a leuco dye and a combination of a triazine compound and a leuco dye are useful.

  In order to improve the thermal stability and storage stability of the photosensitive resin composition, the photosensitive resin composition contains a stabilizer such as the following radical polymerization inhibitor, benzotriazoles, and carboxybenzotriazoles. It is preferable.

  Examples of the radical polymerization inhibitor include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2′-methylenebis. (4-ethyl-6-tert-butylphenol), nitrosophenylhydroxyamine aluminum salt, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), diphenylnitrosamine, pentaerythritol 3,5-di-t- Butyl-4-hydroxyphenylpropionic acid tetraester (ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate] (IRGANOX2 manufactured by Ciba Specialty Chemicals Co., Ltd.) 5)), and the like.

  As another stabilizer, a compound in which propylene oxide is further added to both sides of polypropylene glycol in which an average of 1 mol of propylene oxide is added to both sides of bisphenol A, respectively.

  Examples of benzotriazoles include 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, and bis (N-2-ethylhexyl) aminomethylene-1,2,3-benzo. Examples thereof include triazole, bis (N-2-ethylhexyl) aminomethylene-1,2,3-tolyltriazole, and bis (N-2-hydroxyethyl) aminomethylene-1,2,3-benzotriazole.

  Examples of carboxybenzotriazoles include 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, and N- (N, N-di-2-ethylhexyl). Examples include aminomethylenecarboxybenzotriazole, N- (N, N-di-2-hydroxyethyl) aminomethylenecarboxybenzotriazole, and N- (N, N-di-2-ethylhexyl) aminoethylenecarboxybenzotriazole.

  The total content of the above-described stabilizer in the photosensitive resin composition is preferably 0.01 to 3% by mass, more preferably 0.05 to 1% by mass. This amount is preferably 0.01% by mass or more from the viewpoint of imparting storage stability to the photosensitive resin composition, and is preferably 3% by mass or less from the viewpoint of maintaining sensitivity.

Moreover, the photosensitive resin composition can contain additives, such as a plasticizer, as needed. Examples of such additives include phthalic acid esters such as diethyl phthalate, p-toluenesulfonamide, polypropylene glycol, polyethylene glycol monoalkyl ether, and the like.
In a typical embodiment, an appropriate solvent is added to the photosensitive resin composition for use.

  The film thickness of the photosensitive resin layer is preferably 0.1 to 40 μm from the viewpoint of the effect that the sensitivity is good. From the viewpoint that the above effect is better, the film thickness is more preferably 0.1 to 15 μm, and further preferably 0.1 to 5 μm.

[Production of photosensitive resin laminate]
The photosensitive resin laminated body of this invention can be manufactured by the following methods, for example. The above photosensitive resin composition is dissolved in a suitable solvent such as methyl ethyl ketone, and the resulting photosensitive resin composition solution is applied onto the above-mentioned support film, and the solvent is removed by a drying process, and then the support film A photosensitive resin layer is laminated thereon. Next, the above protective film is laminated on the surface of the photosensitive resin layer opposite to the surface on the support film lamination side by a method such as thermocompression bonding using a laminator. By the above, the photosensitive resin laminated body which has the laminated structure of the order of a support body film, the photosensitive resin layer, and a protective film is obtained. As described above, the protective film has a sufficiently smaller adhesion to the photosensitive resin layer than the support film, and an important characteristic as a protective film is that the protective film can be easily peeled from the photosensitive resin layer.

<Method for forming resist pattern>
In another aspect, the present invention is a method for forming a resist pattern using the above-described photosensitive resin laminate of the present invention, wherein the photosensitive resin layer is laminated on a substrate while peeling off the protective film. A laminating step of forming the photosensitive resin layer on the substrate, an exposure step of exposing the photosensitive resin layer formed on the substrate, and developing the photosensitive resin layer after the exposure And a development step of forming a resist pattern on the substrate. Below, the specific example about the formation method of the resist pattern of this invention is demonstrated.

(A) Lamination process:
In this step, while peeling off the protective film of the photosensitive resin laminate, the photosensitive resin layer and the surface of the substrate (for example, a copper surface) are stacked so as to adhere to each other, and this is placed between a pair of upper and lower hot rolls. The photosensitive resin layer and the substrate are pressure-bonded by laminating the two through the film. Thereby, a photosensitive resin layer is formed on the substrate.

  The temperature of the hot roll is preferably 50 to 120 ° C., and the laminating speed is preferably 0.1 to 6.0 m / min. The pair of upper and lower hot rolls are pinched by an air cylinder or a spring. The roll pressure is preferably 0.1 to 1.0 MPa / cm, more preferably 0.2 to 0.5 MPa / cm, as the pressure per unit length of the hot roll.

  As the laminator, a one-stage laminator that uses a pair of laminate rolls, a multi-stage laminator that uses two or more pairs of laminate rolls, a vacuum laminator that covers the part to be laminated with a container and depressurizes or evacuates with a vacuum pump, etc. are used. The

  In addition, various treatments (pretreatment) may be performed before the lamination in order to improve the adhesion between the substrate and the photosensitive resin layer. For example, as a method for physically roughening the substrate surface, buffalo polishing can be mentioned. Moreover, the acidic liquid which has the capability to corrode copper is used as a pre-processing liquid, and the board | substrate is processed by the immersion method or the spray method with this pre-processing liquid heated at 25-50 degreeC as needed.

  The pretreatment liquid includes a mixed solution of sulfuric acid and hydrogen peroxide solution, an aqueous solution of ammonium persulfate or sodium persulfate, a mixed solution of an aqueous solution of ammonium persulfate or sodium persulfate and sulfuric acid, nitric acid, metal nitrate and organic acid. And a mixed aqueous solution of a metal acetate and an organic acid. Examples of the organic acid include formic acid, acetic acid, malic acid, acrylic acid, glycolic acid, maleic acid, itaconic acid, maleic anhydride and the like.

  A chemical solution that is commercially available as a chemical polishing agent, a soft etching agent, or a surface roughening agent and that contains the above components can also be preferably used. Examples include CPE-900 and CPE-500 (both made by Mitsubishi Gas Chemical, trade name), and CZ-8100 and CB-801 (both made by MEC, trade name).

(B) Exposure process:
In this step, the photosensitive resin layer formed on the substrate is exposed. Preferably, the photomask on which a desired conductor pattern is drawn is placed on a support film through a minute gap, or is exposed using an ultraviolet light source in a state of being in close contact with the support film. Further, the exposure may be performed by forming a photomask image on the photosensitive resin layer using a projection lens. When the photosensitive resin layer is exposed by projecting a photomask image, the support film may be peeled off from the photosensitive resin layer to expose the photosensitive resin layer, or the photosensitive resin may be left with the support film attached. The layer may be exposed. Examples of the ultraviolet light source include a high pressure mercury lamp, an ultra high pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, and a xenon lamp. In order to obtain a finer resist pattern, it is preferable to use a parallel light source.

(C) Development process:
In this step, a resist pattern is formed on the substrate by developing the exposed photosensitive resin layer. When the support film is not peeled from the photosensitive resin layer at the time of exposure, the support film is peeled off. Thereafter, the photosensitive resin layer is developed using an alkali developer. Specifically, when the photosensitive resin layer is made of a negative photosensitive resin composition, the unexposed portion is dissolved or dispersed and removed, and when the photosensitive resin layer is made of a positive photosensitive resin composition, the exposed portion is removed. Dissolve or disperse. Thereby, a resist pattern is formed on the substrate.

  Examples of the alkaline aqueous solution used in the development step include aqueous solutions of sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide and the like. Most commonly, a 0.2 to 2.0% by weight aqueous sodium carbonate solution is used. The washing water after development is preferably water that has not been deionized from the viewpoints of resist pattern adhesion, resolution, and prevention of tailing. For example, tap water is preferred. Through the above steps, a desired resist pattern can be formed.

<Conductor pattern manufacturing method>
In another aspect, the present invention is a method for producing a conductor pattern using the above-described photosensitive resin laminate of the present invention, wherein the photosensitive resin layer is laminated on a substrate while peeling off the protective film. A laminating step of forming the photosensitive resin layer on the substrate, an exposure step of exposing the photosensitive resin layer formed on the substrate, and developing the photosensitive resin layer after the exposure Provided is a method for producing a conductor pattern, which includes a developing step for forming a resist pattern on the substrate and a conductor pattern forming step for etching or plating the substrate on which the resist pattern is formed. In the method for producing a conductor pattern, the laminating step, the exposing step, and the developing step can be performed in the same manner as those steps in the resist pattern forming method described above. In this embodiment, after the resist pattern is formed, the conductor pattern can be manufactured through the following steps.

(D) Conductor pattern forming step:
In this step, the portion of the substrate surface not covered with the resist pattern (for example, a copper surface) is etched with an etching solution while leaving the resist pattern formed on the substrate by the above-described development step, or the resist Plating treatment of copper, solder, nickel, tin, or the like is performed on a portion of the substrate surface (for example, a copper surface) that is not covered with the pattern. Thereby, a conductor pattern is formed.

Peeling process:
In addition, after forming a conductor pattern with the manufacturing method of the conductor pattern of this invention, typically the peeling process which removes a resist pattern from a board | substrate with an alkali peeling liquid is performed. As the alkaline aqueous solution used in the peeling step, an alkaline aqueous solution that is stronger than the alkaline aqueous solution used in the development is used. Examples of the alkaline aqueous solution for peeling include aqueous solutions of sodium hydroxide, potassium hydroxide, organic amine compounds and the like. Most commonly, an aqueous solution of 1-5% by weight sodium hydroxide or potassium hydroxide is used.

  Hereinafter, examples of embodiments of the present invention will be described in more detail. In Table 1, the kind of resin which comprises the protective film of each Example and a comparative example, the kind of antioxidant, the phenol equivalent of antioxidant, content of the antioxidant in a protective film, and photosensitive resin composition The amount of the product is shown. However, among the blending amounts shown in Table 1, B-1 and B-2 are described as the amount of the solution containing the solvent. In addition, Table 2 shows the names of the material components in the photosensitive resin composition preparation liquid represented by abbreviations in Table 1.

1) Production of photosensitive resin laminate A mixed solution of the components shown in Table 1 was uniformly applied onto a support film using a bar coater, dried in a dryer at 95 ° C. for 1 minute, and 10 μm thick photosensitive. A conductive resin layer is formed. Further, a protective film is laminated on the photosensitive resin layer to obtain a photosensitive resin laminate. For the support film, R340G (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., polyethylene terephthalate, thickness of 16 μm) is used. In addition, a 22 μm-thick high-pressure low-density polyethylene film (manufactured by Asahi Kasei Chemicals Corporation, LS2340S) or a 20 μm-thick polypropylene film is used as the protective film.

2) Fabrication of wiring board (flat surface)
A copper clad laminate on which rolled copper foil having a thickness of 35 μm is laminated is used as a substrate, and the surface of the substrate is subjected to wet buffol polishing (manufactured by 3M Co., Ltd., trade name Scotch Bright (registered trademark) # 600, 2 series).
(laminate)
While peeling off the protective film of the photosensitive resin laminate, the photosensitive resin layer is laminated on the substrate using a laminator AL-70 (trade name, manufactured by Asahi Kasei). The laminating conditions are laminating speed: 1.5 m / min, laminating roll temperature: 105 ° C., laminating pressure: 0.35 MPa / cm.
(exposure)
A mask film necessary for the evaluation of the photosensitive resin layer is placed on a polyethylene terephthalate film as a support, and is passed through the mask film with a super-high pressure mercury lamp (HMW-201KB manufactured by Oak Manufacturing Co., Ltd.) at 100 mJ / cm ² . The resin layer is exposed.
(developing)
After peeling off the support film, the photosensitive resin layer is developed by spraying a 1% by mass aqueous sodium carbonate solution at 30 ° C. for about 20 seconds and dissolving and removing unexposed portions.
[Phenol equivalent]
The antioxidant (nominal antioxidant type) contained in the protective film to be used is calculated by dividing the number of structures represented by the general formula (I) by the molecular weight.
[Antioxidant content]
It is the value which divided | segmented the preparation amount of antioxidant in the protective film to be used by the preparation amount of the raw material of the protective film except antioxidant.

[Sensitivity test]
The photosensitive resin laminate in a state where the protective film shown in Table 1 is laminated is laminated to a copper clad laminate while peeling off the protective film, and the resulting laminate is passed through a 27-step step tablet to form a 27-step step. The tablet is exposed at an exposure amount of 13 steps, and then developed with a 1% by weight aqueous sodium carbonate solution at 30 ° C. for a time period twice the minimum development time. The maximum number of remaining film steps of the obtained cured resist is defined as sensitivity. The 27-step tablet used here is a 27-step tablet manufactured by Stofer, in which rectangular masks of various densities are arranged, and the optical density is increased by 0.05 per step. Table 3 shows the number of step tablet used, the optical density, and the light transmittance.
[Adhesion evaluation]
The photosensitive resin laminate in a state where the protective film shown in Table 1 is laminated is laminated on a copper clad laminate while peeling off the protective film, and the substrate for resolution evaluation that has passed for 15 minutes after lamination is independent of various widths. Exposure through a pattern mask consisting of lines. Development is performed with a development time twice as long as the minimum development time, and a minimum mask line width in which a cured resist line is normally formed is defined as an adhesion value.
[Hold time sensitivity test / Hold time adhesion evaluation]
The photosensitive resin laminate with the protective film shown in Table 1 attached is stored in an environment at a temperature of 23 ° C. and a relative humidity of 50%, and after 72 hours, the sensitivity is measured in the same manner as in the sensitivity test and adhesion evaluation. And adhesion are evaluated.
Table 1 shows the sensitivity difference between the sensitivity test and the hold time sensitivity test, and the adhesion difference between the adhesion evaluation and the hold time adhesion evaluation.

The evaluation results of Examples 1 to 5 and 7 to 13, Reference Example 6 and Comparative Example 1 are shown in Table 1 below. From Table 1, in Examples 1 to 5 and 7 to 13 and Reference Example 6 , the sensitivity difference between the sensitivity test and the hold time sensitivity test is within a predetermined range, so that there is no decrease in adhesion at the hold time. I understand that. In Comparative Example 1, it can be seen that, when the difference in sensitivity between the sensitivity test and the hold time sensitivity test exceeds three stages, an adhesion decrease of 15 μm occurs in the hold time adhesion test.

  The present invention is suitably used for manufacturing printed circuit boards, semiconductor package substrates such as BGA and CSP, lead frame substrates, and COF circuit boards.

Claims (4)

A photosensitive resin laminate comprising at least (A) a support film, (B) a photosensitive resin layer comprising a photosensitive resin composition, and (C) a protective film,
The (C) protective film is laminated in contact with the photosensitive resin layer comprising the photosensitive resin composition (B),
The difference between the sensitivity of the photosensitive resin layer in the photosensitive resin laminate immediately after formation and the sensitivity of the photosensitive resin layer in the photosensitive resin laminate after holding for 72 hours at a temperature of 23 ° C. and a relative humidity of 50% after formation. A certain sensitivity difference is 3 steps or less in a 27 step tablet,
The sensitivity is such that the photosensitive resin layer is exposed with an exposure amount of 13 steps for a 27-step tablet, and then developed with a 1% by weight aqueous sodium carbonate solution at 30 ° C. for a time period twice the minimum development time. Expressed as the maximum number of remaining film steps of the cured resist obtained by
The protective film (C) has the following general formula (I):

(In the formula, R ₁ and R ₂ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.)
Containing an antioxidant containing a structure represented by
The phenol equivalent of the antioxidant is 3.1 × 10 ⁻³ or less,
The photosensitive resin laminated body whose content of this antioxidant in this protective film is more than 1 ppm and 3000 ppm or less . The photosensitive resin laminate according to claim 1 , wherein the protective film (C) is a polyethylene film. A method of forming a resist pattern using a photosensitive resin laminate according to claim 1 or 2,
A laminating step of forming the photosensitive resin layer on the substrate by laminating the photosensitive resin layer on the substrate while peeling off the protective film;
An exposure step of exposing the photosensitive resin layer formed on the substrate;
A development step of forming a resist pattern on the substrate by developing the photosensitive resin layer after the exposure;
A method for forming a resist pattern, comprising: A method of manufacturing a conductive pattern by using a photosensitive resin laminate according to claim 1 or 2,
A laminating step of forming the photosensitive resin layer on the substrate by laminating the photosensitive resin layer on the substrate while peeling off the protective film;
An exposure step of exposing the photosensitive resin layer formed on the substrate;
A development step of forming a resist pattern on the substrate by developing the photosensitive resin layer after the exposure;
A conductor pattern forming step of etching or plating the substrate on which the resist pattern is formed;
The manufacturing method of a conductor pattern containing this.