CN111694218A

CN111694218A - Photosensitive resin composition and method for forming circuit pattern

Info

Publication number: CN111694218A
Application number: CN202010587896.3A
Authority: CN
Inventors: 内藤一也; 松田隆之
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2014-05-21
Filing date: 2015-05-21
Publication date: 2020-09-22
Anticipated expiration: 2035-05-21
Also published as: KR20210102494A; TW201708959A; KR20220148301A; TW201602729A; KR20160131084A; CN111694218B; WO2015178462A1; JP6470805B2; TWI623814B; JP2017223993A; TW201820036A; CN106462068B; CN106462068A; KR20190092622A; TWI660241B; TWI570513B; JPWO2015178462A1

Abstract

Provided are a photosensitive resin composition and a method for forming a circuit pattern. A photosensitive resin composition, comprising: (A) alkali-soluble polymer: 40 to 80% by mass, (B) a photopolymerization initiator: 0.1 to 20 mass%, and (C) a compound having an ethylenic double bond: 5 to 50% by mass, a photosensitive resin layer having a thickness of 25 μm and formed from the photosensitive resin composition is formed on the surface of a substrate, the resist pattern obtained by exposure and development is formed such that the position of the focal point at the time of exposure is shifted by 200 μm from the surface of the substrate toward the inside of the substrate in the thickness direction of the substrate, the resist sweep width is 0.01 to 3.5 μm, and the photosensitive resin composition is used for direct image exposure.

Description

Photosensitive resin composition and method for forming circuit pattern

This application is a divisional application of the present invention entitled photosensitive resin composition and method for forming circuit pattern, with application date of 2015, 05, month 21, and application No. 201580025748. X.

Technical Field

The present invention relates to a photosensitive resin composition that can be developed with an alkaline aqueous solution and a circuit pattern forming method using the photosensitive resin composition. More particularly, the present invention relates to precision processing of metal foils for manufacturing printed circuit boards, flexible printed circuit boards, lead frames for mounting IC chips, metal masks, and the like; BGA (ball grid array), CSP (chip size package), and other semiconductor package manufacturing; manufacturing a Tape substrate typified by TAB (Tape automated bonding) and COF (Chip On Film: a Film in which a semiconductor IC is mounted On a Film-like fine circuit board); manufacturing a semiconductor bump; a photosensitive resin composition which can be provided with a resist pattern suitable for the production of a member such as an ITO electrode, an address electrode, or an electromagnetic wave shield in the field of flat panel displays, and a method for forming a circuit pattern using the photosensitive resin composition.

Background

Conventionally, printed wiring boards have been manufactured by photolithography, precision machining of metals, and the like. Photosensitive resin compositions used in photolithography are classified into negative type compositions and positive type compositions. The photolithography method using the negative photosensitive resin composition is performed, for example, as follows:

a negative photosensitive resin composition is applied to a substrate, and pattern exposure is performed to polymerize and cure an exposed portion of the photosensitive resin composition. Next, the unexposed portion is removed with a developing solution to form a resist pattern on the substrate. Further, after a conductor pattern is formed by etching or plating, the resist pattern is peeled off from the substrate, and a conductor pattern is formed on the substrate.

In the case of the photolithography method, when the photosensitive resin composition is applied to a substrate, any of the following methods can be used:

(1) a method of coating a photoresist solution on a substrate and drying it; and

(2) a method of laminating a photosensitive resin layer on a substrate using a photosensitive resin laminate in which a support, a layer formed of a photosensitive resin composition (hereinafter referred to as "photosensitive resin layer"), and a protective layer laminated as necessary are laminated in this order. The latter method is mostly used in the manufacture of printed circuit boards.

Hereinafter, a method for manufacturing a printed wiring board using the photosensitive resin laminate will be briefly described.

First, the protective layer is peeled from the photosensitive resin laminate. Next, the photosensitive resin layer and the support are laminated on a substrate such as a copper-clad laminate in this order using a laminator. Next, the photosensitive resin layer is exposed through a photomask having a desired wiring pattern, and the exposed portion is polymerized and cured. Subsequently, the support is peeled off. Then, the unexposed portion of the photosensitive resin layer is dissolved or dispersed and removed by a developing solution, thereby forming a resist pattern on the substrate.

As the protective layer, for example, a polyethylene film or the like is preferably used;

as the support, for example, a polyethylene terephthalate film or the like is preferably used;

as the developer, for example, an aqueous solution having weak alkalinity or the like is preferably used.

The step of dissolving or dispersing and removing the photosensitive resin layer in the unexposed portion with the developer is referred to as a developing step. Each time this developing process is repeated, the amount of the unexposed portion of the photosensitive resin composition dissolved in the developer increases. Therefore, when the developing process is repeated, the foamability of the developer tends to be high. The foamability of the developer significantly reduces the work efficiency in the developing process.

Next, etching treatment or pattern plating treatment is performed using the resist pattern formed through the above-described development step as a protective mask. Finally, the resist pattern is peeled off from the substrate, thereby manufacturing a substrate (i.e., a printed circuit board) having a conductor pattern.

In recent years, with the miniaturization and weight reduction of electronic devices, the thinning and densification of the line/space (L/S) of wiring are advancing. Further, a Build up substrate (Build up substrate) having a multilayer wiring structure is also in increasing demand. In the lamination process, a technique for accurately aligning the positions of the plurality of substrates is required, and therefore, a photosensitive resin layer to which a Direct Imaging (DI) method having excellent alignment accuracy can be applied has been becoming mainstream. Therefore, high sensitivity and high resolution of the photosensitive resin are required.

In this regard, patent documents 1 and 2 describe photosensitive resin compositions containing a specific alkali-soluble polymer, a monomer, and a photopolymerization initiator, and describe that the photosensitive resin compositions can achieve the above-described high sensitivity and high resolution. Patent document 3 reports that polyalkylene glycol is used as an additive for a photosensitive resin composition in order to suppress the foamability of a developer.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2009/147913

Patent document 2: international publication No. 2010/098175

Patent document 3: japanese laid-open patent publication No. 2012-159651

Disclosure of Invention

Problems to be solved by the invention

In order to cope with the thinning and densification of wiring, it is required to stably realize a finished line width of a conductor (for example, copper wire) after etching. For this reason, the resist width after development needs to be stable. However, a slight sag phenomenon called "resist sag" is often observed at the bottom of the resist layer after development (see fig. 1). The presence of the resist sweep is a significant factor in the fluctuation of the width of the etched wire. In addition, the presence of the resist sweep also significantly affects the adhesion of the resulting conductor pattern to the substrate in a manufacturing method in which a conductor pattern is formed by pattern plating treatment. These phenomena are particularly remarkable in the DI type exposure system used in recent years, and become new problems accompanying the progress of the technology.

The following is considered for the mechanism by which the generation of the resist sag in the DI exposure becomes remarkable. The present invention is not limited to the following theory.

The DI exposure is a method of performing exposure by scanning a laser focal point. The irradiation intensity of the laser focus is based on a gaussian distribution. Therefore, regions with a small exposure amount (weak exposure regions) are generated at both ends of the exposure pattern. Since the cured resist in the weakly exposed region has low developer resistance, it is partially dissolved in a subsequent developing step. It is considered that the dissolution residue at this time is precipitated and deposited on the bottom of the resist layer, thereby causing the resist layer to sag.

This weak exposure area is a particular problem for DI using multiple exposures of the focal point. More importantly, the width of the faint light area is determined to be a fixed value, and therefore the problem becomes more pronounced as the design line width becomes narrower. In order to improve the resolution, each exposure machine manufacturer aims to improve the focal diameter of the laser and the resolution between the focal points. However, it is the actual situation that the performance of the exposure machine does not meet the specifications of the printed circuit board which is becoming higher and higher.

Further, patent document 3 (jp 2012-159651 a) discloses a method of adding polyalkylene glycol as an antifoaming agent to a photosensitive resin composition in order to suppress foamability in a developing step. However, according to the technique of patent document 3, the density of the monomer decreases due to the addition of the defoaming agent, and therefore, the photopolymerization efficiency and sensitivity tend to decrease due to exposure.

Accordingly, an object of the present invention is to provide a photosensitive resin composition for direct imaging having excellent stability of a wire width after etching, excellent adhesion of a plated wire, or both, and a method for forming a circuit pattern using the photosensitive resin composition.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems and have repeatedly conducted experiments. As a result, the present inventors have found that the above problems can be solved by the following technical means, and have completed the present invention.

The present invention discloses the following embodiments.

[1] A photosensitive resin composition, comprising:

(A) alkali-soluble polymer: 40 to 80 mass%,

(B) Photopolymerization initiator: 0.1 to 20 mass%, and

(C) compound having an ethylenic double bond: 5 to 50% by mass of a binder,

a photosensitive resin layer having a thickness of 25 μm formed from the photosensitive resin composition was formed on the surface of a substrate,

the resist pattern obtained by exposure and development under the condition that the position of the focal point at the time of exposure is shifted from the substrate surface to the substrate inner side by 200 [ mu ] m in the thickness direction of the substrate has a resist sweep width of 0.01 [ mu ] m to 3.5 [ mu ] m,

the photosensitive resin composition is used for direct imaging exposure.

[2] The photosensitive resin composition according to the above [1], wherein a photosensitive resin layer having a thickness of 25 μm and formed from the photosensitive resin composition is formed on a surface of a substrate, and when the photosensitive resin layer is exposed with an exposure amount in which the maximum residual film number in the case of exposure using a Schonfish 21-stage exposure scale as a mask and then development is performed is 6 stages,

the value of PxQ/100 is 0.7 or more, where Q is the average number of the olefinic double bonds in the compound (C) and P is the reaction rate of the olefinic double bonds in the compound (C) after the exposure.

[3] The photosensitive resin composition according to the above [1] or [2], wherein a photosensitive resin layer having a thickness of 25 μm and formed from the photosensitive resin composition is formed on a surface of a substrate, and when the photosensitive resin layer is exposed with an exposure amount of 1/10, which is an exposure amount at which the maximum residual film number is 6 when the photosensitive resin layer is exposed with a Schonfish 21-stage exposure scale as a mask and then developed,

the value of P '× Q/100 when the average number of the olefinic double bonds in the compound (C) is represented by Q and the reaction rate of the olefinic double bonds in the compound (C) after the exposure is represented by P' is 0.3 or more.

[4]According to the above [1]]～[3]The photosensitive resin composition according to any one of the above (A) and (B), wherein the weight average Tg of the alkali-soluble polymer is^totalIs 30 ℃ or higher and 125 ℃ or lower.

[5] The photosensitive resin composition according to any one of the above [1] to [4], wherein the compound (C) comprises a compound having 3 or more methacryloyl groups in one molecule.

[6] The photosensitive resin composition according to any one of the above [1] to [5], wherein the compound (C) comprises a compound having 4 or more methacryloyl groups in one molecule.

[7] The photosensitive resin composition according to any one of the above [1] to [6], wherein the compound (C) comprises a compound represented by the following general formula (IV):

{ formula (II) wherein n₁、n₂、n₃And n₄Each independently represents an integer of 1 to 25, n₁+n₂+n₃+n₄Is an integer of 9 to 60, and,

R₁、R₂、R₃and R₄Each independently represents an alkyl group, and each independently represents an alkyl group,

R₅、R₆、R₇and R₈Each independently represents an alkylene group, R₅、R₆、R₇And R₈When there are plural R's, respectively₅、R₆、R₇And R₈The same or different }.

[8]According to the above [7]]The photosensitive resin composition, wherein in the general formula (IV), n₁+n₂+n₃+n₄Is an integer of 15 to 40.

[9]According to the above [7]]The photosensitive resin composition, wherein in the formula (IV), n₁+n₂+n₃+n₄Is an integer of 15 to 28.

[10] The photosensitive resin composition according to any one of the above [1] to [9], wherein the photopolymerization initiator (B) contains an acridine compound.

[11] The photosensitive resin composition according to any one of the above [1] to [10], further comprising a halide.

[12] The photosensitive resin composition according to any one of the above [1] to [11], wherein the photopolymerization initiator (B) contains N-phenylglycine or a derivative thereof.

[13] The photosensitive resin composition according to any one of the above [1] to [12], wherein the alkali-soluble polymer (A) has an aromatic hydrocarbon group.

[14] A photosensitive resin composition, characterized in that the photosensitive resin composition contains:

(A) alkali-soluble polymer: 40 to 80% by mass of a binder,

(B) photopolymerization initiator: 0.1 to 20 mass%, and

(C) compound having an ethylenic double bond: 5 to 50% by mass of a binder,

the compound (C) includes a compound having 3 or more methacryloyl groups in one molecule.

[15] The photosensitive resin composition according to [14], wherein a photosensitive resin layer having a thickness of 25 μm and formed from the photosensitive resin composition is formed on a substrate surface, and when the photosensitive resin layer is exposed with an exposure amount in which the maximum residual film number in the case of exposure using a Schonfish 21-stage exposure scale as a mask and then development is performed is 6 stages,

[16] The photosensitive resin composition according to [14] or [15], wherein a photosensitive resin layer having a thickness of 25 μm and formed from the photosensitive resin composition is formed on a surface of a substrate, and when the photosensitive resin layer is exposed with an exposure amount of 1/10, which is an exposure amount at which the maximum residual film number in the case of exposure using a Schonfish 21-stage exposure scale as a mask and then development is performed, is 6-stage,

[17] The photosensitive resin composition according to any one of [14] to [16], wherein the compound (C) comprises a compound having 4 or more methacryloyl groups in one molecule.

[18] The photosensitive resin composition according to any one of the above [14] to [17], wherein the compound (C) comprises a compound represented by the following general formula (IV):

[19]According to the above [18]]The photosensitive resin composition, wherein in the formula (IV), n₁+n₂+n₃+n₄Is an integer of 15 to 40.

[20]According to the above [18]]The photosensitive resin composition, wherein in the formula (IV), n₁+n₂+n₃+n₄Is an integer of 15 to 28.

[21] The photosensitive resin composition according to any one of the above [14] to [20], wherein the photopolymerization initiator (B) contains an acridine compound.

[22] The photosensitive resin composition according to any one of the above [14] to [21], further comprising a halide.

[23] The photosensitive resin composition according to any one of the above [14] to [22], wherein the photopolymerization initiator (B) contains N-phenylglycine or a derivative thereof.

[24] The photosensitive resin composition according to any one of the above [14] to [23], wherein the alkali-soluble polymer (A) has an aromatic hydrocarbon group.

[25]According to the above [14]]～[24]The photosensitive resin composition according to any one of the above (A) and (B), wherein the weight average Tg of the alkali-soluble polymer is^totalIs 30 ℃ or higher and 125 ℃ or lower.

[26] The photosensitive resin composition according to any one of the above [14] to [25], which is used for direct image-wise exposure.

[27] A method of forming a circuit pattern, comprising:

a step of forming a layer of the photosensitive resin composition according to any one of the above [1] to [26] on a substrate;

a step of forming a resist pattern by exposing and developing the layer of the photosensitive resin composition; and

and etching or plating the substrate on which the resist pattern is formed.

[28] The method according to the foregoing [27], wherein the foregoing exposure is performed by direct imaging exposure.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide a photosensitive resin composition which can suppress the generation of resist sagging, has excellent stability of the width of a wire (for example, a copper wire) after etching and excellent adhesion of a wire after plating, and can be suitably used for forming a circuit pattern by a direct imaging method, and a method for forming a circuit pattern using the photosensitive resin composition.

Drawings

Fig. 1 is a schematic cross-sectional view for explaining the definition of the width of the sag of the resist layer.

Detailed Description

The following describes in detail an embodiment for carrying out the present invention (hereinafter, simply referred to as "embodiment"). The present invention is not limited to the following embodiments, and can be implemented by being variously modified within the scope of the gist thereof.

< photosensitive resin composition >

One embodiment provides a photosensitive resin composition (photosensitive resin composition for direct imaging exposure), which is characterized by containing:

(A) alkali-soluble polymer: 40 to 80 mass%,

(B) Photopolymerization initiator: 0.1 to 20 mass%, and

(C) compound having an ethylenic double bond: 5 to 50% by mass of a binder,

the photosensitive resin composition is used for direct imaging exposure.

Another embodiment provides a photosensitive resin composition, comprising:

(A) alkali-soluble polymer: 40 to 80 mass%,

(B) Photopolymerization initiator: 0.1 to 20 mass%, and

(C) compound having an ethylenic double bond: 5 to 50% by mass of a binder,

The photosensitive resin composition for direct imaging exposure of the present disclosure is a composition that provides the above-mentioned specific resist run-down width to a resist pattern obtained by exposure and development under the above-mentioned conditions. The resist sweep width of a resist pattern obtained by forming a photosensitive resin layer having a thickness of 25 μm formed of a photosensitive resin composition on the surface of a substrate and performing exposure and development under the condition that the position of the focal point at the time of exposure is shifted by 200 μm from the surface of the substrate toward the inner side of the substrate in the thickness direction of the substrate is 0.01 μm to 3.5 μm, which is an important condition contributing to the reduction of the fluctuation in the width of a wire after etching and the improvement of the adhesion of the plated wire. From the viewpoint of improving the adhesion of the cured resist, it is advantageous that the width of the resist skirt is 0.01 μm or more; this value is advantageously 3.5 μm or less from the viewpoint of reducing the fluctuation in the wire width after etching and from the viewpoint of improving the adhesion of the wire after plating. The resist sweep width is preferably 0.02 μm or more, more preferably 0.03 μm or more, preferably 2.5 μm or less, more preferably 2.0 μm or less, further preferably 1.5 μm or less, particularly preferably 1.2 μm or less, and most preferably 1 μm or less.

The more specific steps of the above-described exposure and development are based on the methods described in [ examples ] or methods that can be understood by those skilled in the art to be equivalent thereto.

It is understood that the above-described specific resist sweep width can be achieved by using the respective components (a) to (C) at a specific ratio and, for example, by the following method (without being limited thereto). The following sequentially describes the respective components contained in the photosensitive resin composition of the present embodiment.

Alkali-soluble Polymer (A)

The alkali-soluble polymer (a) of the present embodiment is a polymer that can be dissolved in an alkali aqueous solution. Examples thereof include: the carboxyl group-containing vinyl polymer is preferably a copolymer of monomers selected from (meth) acrylic acid, (meth) acrylic acid esters, (meth) acrylonitrile, (meth) acrylamide, and the like.

(A) The alkali-soluble polymer preferably contains a carboxyl group and has an acid equivalent of 100 to 600. The acid equivalent means a mass in grams of the alkali-soluble polymer having 1 equivalent of a carboxyl group therein. From the viewpoint of improving development resistance, resolution, and adhesion, the acid equivalent is preferably 100 or more, and from the viewpoint of improving development and peeling properties, the acid equivalent is preferably 600 or less. The acid equivalent can be measured by a potentiometric titration method using a 0.1mol/L aqueous solution of sodium hydroxide using a titration apparatus (e.g., a Pingyan automatic titration apparatus (COM-555) manufactured by Pingyan industries, Ltd.). (A) The acid equivalent of the alkali-soluble polymer is more preferably 250 to 450.

(A) The weight average molecular weight of the alkali-soluble polymer is preferably 5000 or more and 500000 or less. From the viewpoint of the properties of the development aggregate and the properties of the unexposed film such as the edge fusibility and the chipping property of the photosensitive resin laminate, the weight average molecular weight is preferably 5000 or more, and from the viewpoint of improving the solubility in the developer, the weight average molecular weight is preferably 500000. The edge-fusion property is a property of suppressing the phenomenon that the photosensitive resin composition layer is extruded from the end face of the roll when the photosensitive resin laminate is wound into a roll. The chipping property is a property of suppressing the scattering of chips when an unexposed film is cut with a cutter. When the swarf property is poor, the following disadvantages occur: the scattered chips adhere to, for example, the upper surface of the photosensitive resin laminate, and the chips are transferred to the mask in the subsequent exposure step, thereby causing defects. (A) The weight average molecular weight of the alkali-soluble polymer is more preferably 5000 to 300000, and still more preferably 10000 to 200000.

(A) The alkali-soluble polymer preferably has an aromatic hydrocarbon group.

(A) The alkali-soluble polymer has an aromatic hydrocarbon group, and thus has advantages of improved resolution and adhesion, reduced generation of aggregates during development, and improved etching resistance.

Aromatic hydrocarbon groups can be introduced into the alkali-soluble polymer (a) by using an aromatic vinyl compound, a (meth) acrylate compound having a benzyl group, or the like as a part of monomers used for synthesis.

(A) The alkali-soluble polymer can be obtained by copolymerizing one or two or more monomers of the following two types of monomers.

The first monomer is a carboxylic acid or an acid anhydride having one polymerizable unsaturated group in the molecule. Examples thereof include: (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, maleic acid half ester, and the like. Particularly preferred is (meth) acrylic acid. Here, (meth) acryloyl represents acryloyl or methacryloyl.

(A) The copolymerization ratio of the first monomer of the alkali-soluble polymer can be easily calculated from a desired acid equivalent value of the alkali-soluble polymer. (A) The copolymerization ratio of the first monomer of the alkali-soluble polymer is preferably 10 to 50% by mass based on the total mass of the total monomer components. From the viewpoint of achieving good developability and the viewpoint of controlling the edge-blending property, the copolymerization ratio is preferably 10% by mass or more. From the viewpoint of improving the resolution, suppressing the generation of resist sagging, and the like, the copolymerization ratio is preferably 50% by mass or less, and from these viewpoints, 30% by mass or less is more preferable, 25% by mass or less is further preferable, and 20% by mass or less is particularly preferable.

The second monomer is a monomer that is non-acidic and has at least one polymerizable unsaturated group in the molecule. Examples thereof include: esters of methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, vinyl alcohol; vinyl acetate; (meth) acrylonitrile; aromatic vinyl compounds, and the like. Examples of the aromatic vinyl compound include styrene and styrene derivatives.

The second monomer is preferably methyl (meth) acrylate, n-butyl (meth) acrylate, styrene, a styrene derivative, or benzyl (meth) acrylate among the above monomers. Among them, styrene derivatives, and benzyl (meth) acrylate are particularly preferable from the viewpoints of improvement in resolution, improvement in adhesion, good development aggregation (a small amount of aggregates), and etching resistance.

As the copolymer component in the alkali-soluble polymer (a), an aromatic monomer such as an aromatic vinyl compound or a (meth) acrylate compound having a benzyl group can be used. (A) The copolymerization ratio of the aromatic monomer compound in the alkali-soluble polymer is preferably 20 to 85 mass% based on the total mass of the total monomer components. From the viewpoints of improving resolution and adhesion, suppressing generation of aggregates during development, improving etching resistance, and the like, the copolymerization ratio is preferably 20% by mass or more, more preferably 25% by mass or more, still more preferably 30% by mass or more, and particularly preferably 40% by mass or more. From the viewpoint of achieving a suitable developability, the copolymerization ratio is preferably 85 mass% or less. In view of cost, the copolymerization ratio of the copolymer component in the alkali-soluble polymer (a) is preferably 20 to 70% by mass based on the total mass of the total monomer components. From the viewpoints of improvement in resolution, improvement in adhesion, development aggregation property, etching resistance, and the like, the copolymerization ratio is preferably 20% by mass or more, more preferably 25% by mass or more, still more preferably 30% by mass or more, and particularly preferably 40% by mass or more. From the viewpoint of achieving appropriate developability and cured film flexibility, the copolymerization ratio is preferably 70% by mass or less, and more preferably 60% by mass or less. In order to put importance on these points, the copolymerization ratio of the aromatic vinyl compound is more preferably 20 to 50% by mass, and particularly preferably 20 to 30% by mass.

In one embodiment, examples of the aromatic vinyl compound include styrene and styrene derivatives. Examples of the styrene derivative include: styrene oxide, hydroxystyrene, acetoxystyrene, alkylstyrene, haloalkylstyrene, and the like.

(A) The alkali-soluble polymer is preferably a copolymer of a monomer mixture containing styrene or a styrene derivative, methyl (meth) acrylate, and (meth) acrylic acid as a comonomer.

In order to obtain excellent resolution, the copolymerization ratio of the aromatic vinyl compound is preferably 40 to 60% by mass based on the total mass of the total monomer components. As the comonomer in this case, styrene or a styrene derivative is preferably contained, and methyl (meth) acrylate and/or (meth) acrylic acid is contained.

In one embodiment, the weight average value Tg of the alkali-soluble polymer (a) in the photosensitive resin composition^totalThe temperature may be in the range of 30 to 125 ℃, preferably 50 to 110 ℃, more preferably 50 to 105 ℃, and still more preferably 50 to 90 ℃. The weight average Tg is preferably 30 ℃ or higher from the viewpoint of controlling the edge fusion property, and is preferably 110 ℃ or lower from the viewpoint of controlling the occurrence of resist sagging. Weight average of Tg in this disclosure Tg^totalIs a value obtained from the following equation (Fox equation):

Tg^total＝Σ_i(W_i×Tg_i)/W^total

{ Here, W_iIs the solid mass of the respective alkali-soluble polymer,

Tg_ithe glass transition temperature of each alkali-soluble polymer determined from the Fox equation,

W^totalis the total value of the solid mass of each alkali-soluble polymer }. Here, the glass transition temperature Tg of each alkali-soluble polymer was determined from the Fox equation_iIn such a case, the Tg of a homopolymer formed from a comonomer forming each alkali-soluble polymer is required. In the present disclosure, literature values are used for this value (Brandrup, j.immergut, e.h. editions, Polymer handbook, Third edition, John wire&sons,1989,Chapter VI“Glass transition temperaturesof polymers”,209Page).

Tg of the individual comonomers used for the calculation in the examples_iShown in Table 4.

The following is considered for the mechanism by which the resist sagging during DI exposure can be suppressed by using the alkali-soluble polymer (a) having the above-described composition. The present invention is not limited to the following theory.

Upon DI exposure, weak exposure areas appear on both sides of the exposure pattern. The reactivity of the resist in the weakly exposed areas decreases. This reduces the developer resistance of the cured resist layer in this region, and therefore the cured resist layer is partially dissolved in the subsequent developing step. It is presumed that the dissolved residue at this time precipitates and deposits on the bottom of the resist layer, thereby causing the resist layer to sag.

Therefore, it is considered that in order to suppress the generation of resist sagging, it is necessary to efficiently cure the monomer in the resist even in the weakly exposed regions. It is believed that the reactivity of the monomers is influenced by the diffusion rate of the monomers, which is governed by the free volume in the resist.

From this fact, it is considered that the composition and structure of the alkali-soluble polymer (a) are designed so that the free volume in the resist layer becomes large, thereby increasing the reaction rate of the monomer and suppressing the resist sagging in the weakly exposed region.

As an index of the free volume, the glass transition temperature Tg is generally used. Tg is the temperature at which the fraction of free volume in the total volume of the polymer begins to increase. Therefore, it is considered that the free volume gradually increases in proportion to the temperature difference of Tg at a temperature of Tg or higher.

The higher the Tg of a material, the smaller the free volume becomes, and the lower the Tg, the larger the free volume becomes, under the same temperature conditions. Therefore, it is considered that the resist composition having a high Tg is likely to have a decreased monomer reaction rate, and therefore, resist sagging occurs, and the resist composition having a low Tg can suppress the occurrence of resist sagging.

For this reason, the weight average Tg of the (A) alkali-soluble polymer^totalLow is preferred, and if the control of the edge fusion is taken into consideration, Tg is preferred^totalAt high times of day isIt is preferred. The result is Tg in view of their compatibility balance^totalThe above-described preferred ranges can be exemplified.

In one embodiment, the amount of the alkali-soluble polymer (a) to be blended in the photosensitive resin composition is preferably in the range of 40 to 80% by mass, more preferably 50 to 70% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. From the viewpoint of controlling the marginal fusion property, the blending amount is preferably 40% by mass or more, and from the viewpoint of controlling the development time, the blending amount is preferably 80% by mass or less.

[ photopolymerization initiator (B) ]

In the embodiment of the present invention, as the (B) photopolymerization initiator, various substances usable as photopolymerization initiators for photosensitive resins can be used.

As the photopolymerization initiator (B) in the present embodiment, for example, 1 or more selected from the group consisting of acridine compounds, N-aryl- α -amino acid compounds, and triarylimidazole dimers can be used. From the viewpoint of achieving high sensitivity and from the viewpoint of achieving both high sensitivity and suppression of resist sagging, acridine compounds are preferred;

from the viewpoint of more reliably suppressing the generation of the resist layer, triarylimidazole dimer is preferable.

Examples of the acridine compound include: 1, 7-bis (9, 9' -acridinyl) heptane, 9-phenylacridine, 9-methylacridine, 9-ethylacridine, 9-chloroethylacridine, 9-methoxyacridine, 9-ethoxyacridine, 9- (4-methylphenyl) acridine, 9- (4-ethylphenyl) acridine, 9- (4-n-propylphenyl) acridine, 9- (4-n-butylphenyl) acridine, 9- (4-tert-butylphenyl) acridine, 9- (4-methoxyphenyl) acridine, 9- (4-ethoxyphenyl) acridine, 9- (4-acetylphenyl) acridine, 9- (4-dimethylaminophenyl) acridine, 9- (4-chlorophenyl) acridine, 9-methylacridine, 9-ethylacridine, 9-n-propylphenyl) acridin, 9- (4-bromophenyl) acridine, 9- (3-methylphenyl) acridine, 9- (3-tert-butylphenyl) acridine, 9- (3-acetylphenyl) acridine, 9- (3-dimethylaminophenyl) acridine, 9- (3-diethylaminophenyl) acridine, 9- (3-chlorophenyl) acridine, 9- (3-bromophenyl) acridine, 9- (2-pyridyl) acridine, 9- (3-pyridyl) acridine, and 9- (4-pyridyl) acridine. Among them, 1, 7-bis (9, 9' -acridinyl) heptane or 9-phenylacridine is preferable from the viewpoints of sensitivity, resolution, availability, and the like.

Examples of the N-aryl- α -amino acid compound include: n-phenylglycine, N-methyl-N-phenylglycine, N-ethyl-N-phenylglycine, and the like. N-phenylglycine has a high sensitizing effect and is particularly preferred.

Examples of triarylimidazole dimers include: 2,4, 5-triarylimidazole dimers such as 2- (o-chlorophenyl) -4, 5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4, 5-bis (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4, 5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4, 5-diphenylimidazole dimer, and 2- (p-methoxyphenyl) -4, 5-diphenylimidazole dimer.

The acridine compound has higher sensitivity than the triarylimidazole dimer compound. Further, when a urethane compound is used as the compound having an ethylenic double bond (C), it is preferable from the viewpoint that both foamability and development aggregation property can be suppressed in combination therewith.

From the viewpoint of improving sensitivity, N-phenylglycine and derivatives thereof are preferable. It is particularly preferable from the viewpoint that generation of resist sagging can be more reliably suppressed when N-phenylglycine or a derivative thereof is used in combination with an acridine compound.

In a preferred embodiment, the photopolymerization initiator (B) preferably contains 1 or more selected from the group consisting of acridine compounds, N-phenylglycine, and N-phenylglycine derivatives. The acridine compound preferably contains 1 or more selected from the group consisting of 9-phenylacridine represented by the following formula (I) and a compound represented by the following general formula (II):

(in the formula, R₁An alkylene group having 1 to 12 carbon atoms).

These compounds are advantageous from the viewpoint of improving sensitivity upon DI exposure. From the viewpoint of solubility, R in the general formula (II)₁The carbon number of (2) is preferably 1 to 12. R₁The carbon number of (2) is more preferably 4 to 10.

As the acridine compound, 9-phenylacridine represented by the above formula (I) is preferably used.

The photopolymerization initiator (B) of the present embodiment may be used alone or in combination with 1 or more selected from the group consisting of acridine compounds, N-phenylglycine or its derivatives, and triarylimidazole dimers.

Further examples of the photopolymerization initiator (B) include: aromatic ketones such as benzophenone, N '-tetramethyl-4, 4' -dimethylaminobenzophenone (michler's ketone), N' -tetraethyl-4, 4 '-diaminobenzophenone, 4-methoxy-4' -dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, and 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholino-1-propanone;

quinones such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1, 2-benzanthraquinone, 2, 3-benzanthraquinone, 2-phenylanthraquinone, 2, 3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1, 4-naphthoquinone, 9, 10-phenanthrenequinone, 2-methyl-1, 4-naphthoquinone, and 2, 3-dimethylanthraquinone;

benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether;

benzil derivatives such as benzil methyl ketal;

a coumarin-based compound;

4, 4' -bis (diethylamino) benzophenone;

pyrazoline derivatives such as 1-phenyl-3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) pyrazoline, 1-phenyl-3- (4-biphenylyl) -5- (4-tert-butylphenyl) pyrazoline, and 1-phenyl-3- (4-biphenylyl) -5- (4-tert-octylphenyl) pyrazoline.

(B) The photopolymerization initiator may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The amount of the photopolymerization initiator (B) to be added to the photosensitive resin composition is 0.1 to 20% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. The amount of the compound is 0.1 mass% or more from the viewpoint of obtaining an exposure pattern having a sufficient residual film ratio after development, and is 20 mass% or less from the viewpoint of obtaining a high resolution by sufficiently transmitting light to the bottom surface of the resist layer and from the viewpoint of suppressing development aggregation in a developer. The preferable range of the amount of the compound is 0.3 to 10% by mass.

(B) When the photopolymerization initiator contains an acridine compound, the amount of the acridine compound added is preferably 0.01 to 5% by mass based on the total solid content mass of the photosensitive resin composition. From the viewpoint of obtaining good sensitivity, the amount of the compound is preferably 0.01% by mass or more. The amount of the compound is more preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more. On the other hand, from the viewpoint of adjusting the resist layer shape to a rectangular shape and improving the color stability of the photosensitive resin composition, the blending amount is preferably 5 mass% or less. The amount of the compound is more preferably 3% by mass or less, and particularly preferably 2% by mass or less.

(B) When the photopolymerization initiator contains an N-aryl- α -amino acid compound, the content of the N-aryl- α -amino acid compound is preferably 0.001 to 5% by mass based on the total solid content of the photosensitive resin composition. From the viewpoint of obtaining good sensitivity, the amount of the compound is preferably 0.001 mass% or more. When the N-aryl- α -amino acid compound and the acridine compound are used in combination, it is particularly preferable from the viewpoint that the generation of resist sagging can be more reliably suppressed. The amount of the compound is more preferably 0.01% by mass or more, still more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more. On the other hand, from the viewpoint of improving resolution and improving color stability of the photosensitive resin composition, the blending amount is preferably 5% by mass or less. The amount of the compound is more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

(B) When the photopolymerization initiator contains a triarylimidazole dimer, the content of the triarylimidazole dimer is preferably 0.1 to 15% by mass based on the total solid content of the photosensitive resin composition. From the viewpoint of obtaining good sensitivity, the amount of the compound is preferably 0.1% by mass or more. The amount of the compound is more preferably 1% by mass or more, and particularly preferably 3% by mass or more. On the other hand, from the viewpoint of obtaining high resolution and suppressing aggregation in the developer, the amount of the compound is preferably 15% by mass or less. The amount of the compound is more preferably 10% by mass or less, and particularly preferably 6% by mass or less.

< Compound having an ethylenic double bond >

In an embodiment of the present invention, the photosensitive resin composition includes (C) a compound having an ethylenic double bond. Preferable examples of the compound include compounds (polyfunctional monomers) having a methacrylate group having 3 or more functions (having 3 or more methacryloyl groups in one molecule) and a molecular weight of 500g/mol or more and 5000g/mol or less. The compound (C) is more preferably a compound having 4 or more functional methacrylate groups (having 4 or more methacryloyl groups in one molecule).

The following is considered for the mechanism by which the resist sagging during DI exposure can be suppressed by using the compound (C). The present invention is not limited to the following theory.

As described above, upon DI exposure, weak exposure regions appear on both sides of the exposure pattern. It is also presumed that the reaction rate of the resist existing in this region is lowered, and thus the resistance of the developing solution is lowered, and the resist layer is lowered. Therefore, in order to suppress the generation of resist sagging, it is necessary to increase the reaction rate of the compound (C) even in the weakly exposed regions to increase the crosslinking density and improve the developer resistance.

In order to crosslink a resist, it is necessary to react one double bond in a certain polyfunctional monomer and then further react the other unreacted double bonds in the same monomer. Therefore, the more the compound (C) has double bonds and the less the unreacted double bonds remaining after exposure, the greater the crosslinking density.

However, the polyfunctional monomer in which the double bond has reacted once is absorbed into the growing polymer chain of high molecular weight. Therefore, in order to react two or more double bonds in a polyfunctional monomer molecule, it is necessary to react a double bond pendant from a growing polymer chain with another monomer or a growing polymer. This reaction is disadvantageous because of its large steric hindrance. In order to promote the reaction by alleviating the steric hindrance of the reaction, it is necessary to extend the length of the molecular chain between the double bonds in the compound (C). Therefore, the molecular weight of the compound (C) is preferably large. On the other hand, if the molecular weight is too large, the reaction rate of the double bonds of the compound (C) increases, but the amount of the double bonds in the composition decreases, and therefore, in this case, the crosslinking density also decreases.

Therefore, in order to suppress resist sagging upon DI exposure, a methacrylate monomer which is a high molecular weight material and has a large number of functional groups is considered to be particularly effective.

From such a viewpoint, the compound (C) of the present embodiment has an optimum molecular weight and an optimum range of the number of functional groups. (C) The molecular weight of the compound is preferably 500g/mol or more and 5000g/mol or less, more preferably 600g/mol or more and 4000g/mol or less, and further preferably 700g/mol or more and 3000g/mol or less.

The number of functional groups in the compound (C) is preferably 3 or more, more preferably 4 or more, from the viewpoints of increasing the crosslinking density, improving the resolution and adhesion, and suppressing the generation of resist sagging. From the viewpoint of suppressing the edge fusion property, the functionality is also preferably 3 or more, and more preferably 4 or more. From the viewpoint of peeling properties, the functionality is preferably 10 or less, more preferably 6 or less, still more preferably 5 or less, and particularly preferably 4 or less. Therefore, in order to achieve an improvement in resolution, suppression of the occurrence of resist sagging, control of edge fusion, and peeling characteristics at a high level, a 4-functional group is most preferable.

In addition, a methacrylate monomer having low hydrolyzability is effective from the viewpoint of developer resistance of the monomer crosslinked body. The methacrylate monomer is preferable from the viewpoint of improving resolution and adhesion, suppressing generation of resist sagging, and controlling edge fusion.

In the embodiment of the present invention, the photosensitive resin composition preferably contains a compound represented by the following general formula (III) as (C) the compound having an ethylenic double bond:

{ formula (II) wherein n₁、n₂And n₃Each independently is an integer of 1 to 25, wherein n₁+n₂+n₃Is an integer of 3 to 75, and,

R₁、R₂and R₃Each independently is alkyl }.

In the general formula (V), n₁+n₂+n₃The value of (d) is preferably 3 or more and 50 or less. From the viewpoint of suppressing the generation of resist sagging, the viewpoint of imparting flexibility to the cured film, and the viewpoint of improving the penetration resistance (resistance film penetration-resistance) of the support film, n is preferably used₁+n₂+n₃It is preferably 3 or more, and n is preferably n from the viewpoint of obtaining high resolution, adhesiveness, and good peeling property₁+n₂+n₃Is set to 50 or less. n is₁+n₂+n₃More preferred range of (b) is 6 to 40, and still more preferred range of (b) is 9 to 30.

Specific examples of the compound represented by the above general formula (III) include:

a trimethacrylate obtained by adding ethylene oxide in an amount of 3 moles on average to a hydroxyl terminal of trimethylolpropane,

A trimethacrylate obtained by adding ethylene oxide in an amount of 9 moles on average to a hydroxyl terminal of trimethylolpropane,

A trimethacrylate obtained by adding ethylene oxide in an amount of 15 moles on average to a hydroxyl terminal of trimethylolpropane,

And trimethacrylates obtained by adding 30 moles of ethylene oxide on average to the hydroxyl terminal of trimethylolpropane.

In one embodiment, the photosensitive resin composition preferably contains a compound represented by the following general formula (IV) as (C) the compound having an ethylenic double bond:

{ formula (II) wherein n₁、n₂、n₃And n₄Each independently represents an integer of 1 to 25, n₁+n₂+n₃+n₄Is an integer of 4 to 100, and,

In the general formula (IV), n₁+n₂+n₃+n₄Preferably 9 or more and 60 or less. From the viewpoint of suppressing the generation of resist sagging, from the viewpoint of improving the puncture resistance of the support film, and from the viewpoint of imparting flexibility to the cured film, n is preferably set to₁+n₂+n₃+n₄On the other hand, from the viewpoint of improving resolution and adhesiveness, obtaining good peeling characteristics, and controlling edge fusion, n is preferably set to 9 or more₁+n₂+n₃+n₄The number is set to 60 or less. Further, n₁+n₂+n₃+n₄More preferred range of (b) is 9 to 40, still more preferred range is 15 to 40, and particularly preferred range is 15 to 28.

As R in the general formula (IV)₅、R₆、R₇And R₈The monomer may be 1, 2-ethylene, 1, 2-propylene, butylene, or the like, and 1, 2-ethylene is preferable from the viewpoint of imparting flexibility to the cured film, from the viewpoint of improving the puncture resistance of the support film, from the viewpoint of suppressing development aggregation, and from the viewpoint of improving the reactivity of the olefinic double bond. Therefore, as the compound represented by the general formula (IV), a compound represented by the following general formula (V) is preferable:

[ in the formula, n₁、n₂、n₃And n₄Each independently is an integer of 1 to 25, wherein n₁+n₂+n₃+n₄Is an integer of 4 to 100, and,

R₁、R₂、R₃and R₄Each independently is alkyl }. n is₁+n₂+n₃+n₄The preferred ranges of (a) are the same as described above.

Specific examples of the compound represented by the above general formula (IV) include: :

a tetramethylacrylate obtained by adding an average of 9 moles of ethylene oxide to the hydroxyl terminal of pentaerythritol,

A tetramethylacrylate obtained by adding an average of 12 moles of ethylene oxide to the hydroxyl terminal of pentaerythritol,

A tetramethylacrylate obtained by adding an average of 15 moles of ethylene oxide to the hydroxyl terminal of pentaerythritol,

A tetramethylacrylate obtained by adding an average of 20 moles of ethylene oxide to the hydroxyl terminal of pentaerythritol,

A tetramethylacrylate obtained by adding an average of 28 moles of ethylene oxide to the hydroxyl terminal of pentaerythritol,

And tetramethylacrylate obtained by adding an average of 35 moles of ethylene oxide to the hydroxyl terminal of pentaerythritol.

In one embodiment, the photosensitive resin composition preferably contains a compound represented by the following general formula (VI) as the (C) compound having an olefinic double bond:

{ formula (II) wherein R₃And R₄Each independently is a hydrogen atom or a methyl group;

n₉and n₁₁Each independently an integer of 0 to 20, and n₉+n₁₁Is an integer of 0 to 20;

n₈and n₁₀Each independently an integer of 1 to 20, and n₈+n₁₀Is an integer of 2 to 20;

-(C₂H₄o) -and- (C)₃H₆Arrangement of repeating units of O) -being random or block, - (C)₂H₄O) -and- (C)₃H₆Any of O) -may be bonded to a bisphenol structure }.

In the general formula (VI), n₈+n₉+n₁₀+n₁₁Preferably 2 or more and 40 or less. From the viewpoint of obtaining flexibility of the cured film, n is preferably used₈+n₉+n₁₀+n₁₁It is preferably 2 or more, and n is preferably n from the viewpoint of obtaining resolution₈+n₉+n₁₀+n₁₁The content is set to 40 or less. Furthermore, n for chemical resistance₈+n₉+n₁₀+n₁₁More preferably, the range of (b) is 4 to 20 inclusive, and still more preferably 6 to 12 inclusive. In addition, n is a number for obtaining the covering property (テント property)₈+n₉+n₁₀+n₁₁More preferably, the range of (b) is 16 to 40 inclusive, and still more preferably 30 to 40 inclusive. n is₉+n₁₁Is an integer of 1 to 20, n₈+n₁₀More preferably an integer of 2 to 20.

Specific examples of the compound represented by the above general formula (VI) include: :

ethylene glycol dimethacrylate obtained by adding ethylene oxide in an average amount of 2 moles to both ends of bisphenol A,

Ethylene glycol dimethacrylate obtained by adding ethylene oxide of 5 moles on average to both ends of bisphenol A,

A dimethacrylate of an alkylene glycol obtained by adding an average of 6 moles of ethylene oxide and an average of 2 moles of propylene oxide to both ends of bisphenol A,

And alkylene glycol dimethacrylate which is alkylene glycol dimethacrylate obtained by adding ethylene oxide in an average amount of 15 moles and propylene oxide in an average amount of 2 moles to both ends of bisphenol a.

In one embodiment, the photosensitive resin composition may contain, as the compound (C) having an olefinic double bond, only the compounds represented by the above general formulae (III), (IV), and (VI), respectively, and may further contain another compound (C).

As the other compound (C), an ethylenically unsaturated compound which can be photopolymerized can be used. Examples of such photopolymerizable ethylenically unsaturated compounds include compounds having 1 ethylenic double bond, compounds having 2 ethylenic double bonds, and compounds having 3 or more ethylenic double bonds.

Examples of the compound having 1 olefinic double bond include compounds obtained by adding (meth) acrylic acid to one terminal of a polyalkylene oxide;

and compounds obtained by adding (meth) acrylic acid to one terminal of a polyalkylene oxide and etherifying the other terminal with an alkyl group or allyl group.

Examples of the compound having 2 olefinic double bonds in the molecule include compounds having (meth) acryloyl groups at both ends of an alkylene oxide chain;

a compound having a (meth) acryloyl group at each end of an alkylene oxide chain obtained by bonding ethylene oxide units and propylene oxide units randomly, alternately, or in blocks;

and compounds having a (meth) acryloyl group at both ends of alkylene oxide-modified bisphenol a.

Among these compounds, compounds having (meth) acryloyl groups at both ends of alkylene oxide-modified bisphenol a are preferred from the viewpoint of resolution and adhesion. Examples of the above-mentioned alkylene oxide modification include: ethylene oxide modification, propylene oxide modification, butylene oxide modification, pentylene oxide modification, hexylene oxide modification, and the like. More preferably, bisphenol A modified with ethylene oxide has (meth) acryloyl groups at both ends.

The compound having 3 or more olefinic double bonds in the molecule can be obtained, for example, as follows:

as the central skeleton, a compound having 3 or more moles of a group capable of adding an alkyleneoxy group to the molecule is used, and an alkyleneoxy group such as an ethyleneoxy group, an propyleneoxy group, or a butyleneoxy group is added to the compound to obtain an alcohol, and the alcohol is used to prepare a (meth) acrylate. In this case, examples of the compound capable of serving as a central skeleton include: glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, compounds having an isocyanurate ring, and the like.

Specific examples of the compound having 3 or more olefinic double bonds in the molecule include: polypropylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate, 2-di (p-hydroxyphenyl) propane (meth) acrylate, glycerol tri (meth) acrylate, trimethylol tri (meth) acrylate, polyoxypropylene trimethylolpropane tri (meth) acrylate, polyoxyethylene trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylpropane triglycidyl ether tri (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, and the like.

The other compounds (C) may be used alone or in combination of 2 or more.

The amount of the compound (C) having an ethylenic double bond in the photosensitive resin composition is 5 to 50% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. The blending amount is 5 mass% or more from the viewpoint of improving sensitivity, resolution, and adhesion, while the blending amount is 50 mass% or less from the viewpoint of suppressing edge fusion and the viewpoint of suppressing peeling delay of the cured resist layer. The amount of the additive is more preferably 25 to 45% by mass.

(C) When the compound having an ethylenic double bond includes the compound represented by the above formula (III), the amount of the compound to be blended is preferably 2% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 30% by mass or less, and further preferably 10% by mass or more and 20% by mass or less, when the total solid content mass of the photosensitive resin composition is 100% by mass.

(C) When the compound having an ethylenic double bond includes the compound represented by the above formula (IV), the amount of the compound to be blended is preferably 2% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 30% by mass or less, and further preferably 10% by mass or more and 20% by mass or less, when the total solid content mass of the photosensitive resin composition is 100% by mass.

(C) When the compound having an ethylenic double bond includes the compound represented by the above formula (VI), the amount of the compound to be blended is preferably 2% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 30% by mass or less, and further preferably 10% by mass or more and 20% by mass or less, when the total solid content mass of the photosensitive resin composition is 100% by mass.

< leuco dye, fluorane dye, coloring matter >

The photosensitive resin composition of the present invention may contain 1 or more selected from leuco dyes, fluorane dyes, and coloring substances. By containing these components in the photosensitive resin composition, the exposed portion develops color. Therefore, it is preferable from the viewpoint of visibility. Further, it is also advantageous in that when a position alignment mark used for exposure is read by a tester or the like, the contrast between an exposed portion and an unexposed portion becomes large and is easily recognized.

Examples of the leuco dye include tris (4-dimethylaminophenyl) methane [ leuco crystal violet ], bis (4-dimethylaminophenyl) phenylmethane [ leuco malachite green ], and the like. In particular, from the viewpoint of improving the contrast, leuco crystal violet as a leuco dye is preferably used.

The content of the leuco dye in the photosensitive resin composition is preferably 0.1 to 10% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. From the viewpoint of improving the contrast between the exposed portion and the unexposed portion, the content is preferably 0.1% by mass or more. The content is more preferably 0.2% by mass or more, and still more preferably 0.3% by mass or more. On the other hand, from the viewpoint of maintaining the storage stability of the photosensitive resin composition and from the viewpoint of suppressing generation of aggregates during development, the content is preferably 10% by mass or less. The content is more preferably 5% by mass or less, and still more preferably 1% by mass or less.

Examples of the coloring substance include: magenta, phthalocyanine GREEN, auramine base, parafuchsin (para magenta), crystal violet, methyl orange, nile blue 2B, victoria blue, malachite GREEN (manufactured by pau koku co., アイゼン (registered trademark) MALACHITE GREEN), basic blue 20, malachite GREEN (manufactured by pau koku co., アイゼン (registered trademark) DIAMOND GREEN GH), and the like.

The content of the coloring material in the photosensitive resin composition is preferably 0.001 to 1% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. From the viewpoint of improving the workability, the content is preferably 0.001 mass% or more, and from the viewpoint of maintaining the storage stability, the content is preferably 1 mass% or less.

< halides >

In the photosensitive resin composition of the present embodiment, a leuco dye and the following halide are preferably used in combination from the viewpoint of adhesion and contrast.

Examples of the halide include: bromopentane, bromoisopentane, brominated isobutene, brominated ethylene, benzhydryl bromide, benzyl bromide, dibromomethane, tribromomethyl phenylsulfone, carbon tetrabromide, tris (2, 3-dibromopropyl) phosphate, trichloroacetamide, iodopentane, iodoisobutane, 1,1, 1-trichloro-2, 2-bis (p-chlorophenyl) ethane, chlorinated triazine compounds, and the like. Tribromomethylsulfone is particularly preferred. From the viewpoints of a large effect, an improvement in resolution, an improvement in adhesion, an improvement in sensitivity, an improvement in contrast, an improvement in puncture resistance of a support film, suppression of the generation of resist sagging, and an improvement in etching resistance when used in combination with an acridine compound, a halide such as tribromomethylsulfonylmethane is preferable.

From the above viewpoint, the content of the halide in the photosensitive resin composition is preferably 0.01% by mass, assuming that the total solid content of the photosensitive resin composition is 100% by mass. The content is more preferably 0.1% by mass or more, still more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more. In addition, from the viewpoint of maintaining the storage stability of the hue of the photosensitive layer and the viewpoint of suppressing generation of aggregates at the time of development, the content is preferably 3% by mass or less. The content is more preferably 2% by mass or less, and still more preferably 1.5% by mass or less.

< radical polymerization inhibitor, benzotriazoles, carboxybenzotriazoles >

In the present embodiment, in order to improve the thermal stability and storage stability of the photosensitive resin composition, the photosensitive resin composition may further contain at least 1 or more compounds selected from the group consisting of radical polymerization inhibitors, benzotriazoles, and carboxybenzotriazoles.

Examples of the radical polymerization inhibitor include: p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, t-butylcatechol, bisphenol, cuprous chloride, 2, 6-di-t-butyl-p-cresol, 2 '-methylenebis (4-methyl-6-t-butylphenol), 2' -methylenebis (4-ethyl-6-t-butylphenol), 4 '-thiobis (6-t-butyl-m-cresol), 4' -butylidenebis (3-methyl-6-t-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, styrenated phenol (for example, available from Kazuku chemical Co., Ltd., trade name "アンテージ SP"), tribenzylphenol (for example, available from Kazuku chemical Co., Ltd., product name "アンテージ SP"), and the like, A phenol compound having 1 to 3 benzyl groups, a trade name "TBP"), nitrosophenylhydroxylamine aluminum salt, diphenylnitrosamine, and the like.

Examples of benzotriazoles include: 1,2, 3-benzotriazole, 1-chloro-1, 2, 3-benzotriazole, bis (N-2-ethylhexyl) aminomethylene-1, 2, 3-methylbenzotriazole, bis (N-2-hydroxyethyl) aminomethylene-1, 2, 3-benzotriazole and the like.

Examples of carboxybenzotriazoles include: 4-carboxy-1, 2, 3-benzotriazole, 5-carboxy-1, 2, 3-benzotriazole, N- (N, N-di-2-ethylhexyl) aminomethylene carboxybenzotriazole, N- (N, N-di-2-hydroxyethyl) aminomethylene carboxybenzotriazole, N- (N, N-di-2-ethylhexyl) aminoethylene carboxybenzotriazole and the like.

The total content of the radical polymerization inhibitor, the benzotriazole compound, and the carboxybenzotriazole compound is preferably 0.01 to 3 mass%, more preferably 0.05 to 1 mass%, based on the total content of the radical polymerization inhibitor, the benzotriazole compound, and the carboxybenzotriazole compound, when the total solid content of the photosensitive resin composition is 100 mass%. From the viewpoint of imparting storage stability to the photosensitive resin composition, the content is preferably 0.01% by mass or more, and from the viewpoint of maintaining sensitivity and suppressing dye discoloration, the content is preferably 3% by mass or less.

< plasticizer >

The photosensitive resin composition of the present embodiment may contain a plasticizer as needed. Examples of the plasticizer include: ethylene glycol esters such as polyethylene glycol, polypropylene glycol, polyoxypropylene polyoxyethylene ether, polyoxyethylene monomethyl ether, polyoxypropylene monomethyl ether, polyoxyethylene monoethyl ether, polyoxypropylene monoethyl ether, and polyoxyethylene polyoxypropylene monoethyl ether;

phthalic acid esters such as diethyl phthalate;

o-toluenesulfonamide, p-toluenesulfonamide, tributyl citrate, triethyl citrate, acetyl tri-n-propyl citrate, acetyl tri-n-butyl citrate, and the like;

propylene glycol obtained by adding propylene oxide to both ends of bisphenol a, ethylene glycol obtained by adding ethylene oxide to both ends of bisphenol a, and the like. These may be used alone in 1 kind or in combination of 2 or more kinds.

In particular, p-toluenesulfonamide is preferably used as the plasticizer from the viewpoints of improvement of peeling properties, reduction in deterioration of resolution and adhesion, suppression of generation of resist sagging, improvement of flexibility of a cured film, and improvement of puncture resistance of a support film.

The content of the plasticizer in the photosensitive resin composition is preferably 1 to 50% by mass, more preferably 1 to 30% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. From the viewpoint of suppressing the delay of the development time and imparting flexibility to the cured film, the content is preferably 1 mass% or more, and from the viewpoint of suppressing the insufficient curing and the edge fusion, the content is preferably 50 mass% or less.

< solvent >

The photosensitive resin composition can be dissolved in a solvent and used as a solution. Examples of the solvent used include:

ketones represented by Methyl Ethyl Ketone (MEK);

alcohols typified by methanol, ethanol, and isopropanol, and the like. The solvent is preferably added to the photosensitive resin composition so that the viscosity of the solution of the photosensitive resin composition applied to the support film is 500 to 4000 mPas at 25 ℃.

< characteristics of photosensitive resin composition >

In the photosensitive resin composition of the present embodiment, a photosensitive resin layer having a thickness of 25 μm is formed on a substrate surface, and when the photosensitive resin layer is exposed to an exposure amount of 6 steps at the highest residual film number in the case of exposure using a schleph 21-step exposure scale as a mask and then development,

the value of P × Q/100 is preferably 0.7 or more, where Q represents the average number of the olefinic double bonds in the compound (C) and P represents the reaction rate of the olefinic double bonds in the compound (C) after the exposure.

This important condition is a preferable important condition for curing the resist pattern to sufficiently react the olefinic double bonds to achieve a sufficient crosslink density and to suppress generation of resist sagging in the weakly exposed regions. In order to suppress the generation of the resist sweep as much as possible, the value of P × Q/100 is more preferably 1.0 or more, still more preferably 1.5 or more, still more preferably 1.7 or more, particularly preferably 2.0 or more, and most preferably 2.5 or more. On the other hand, in order to easily peel off a used resist pattern after forming a circuit pattern, the value of P × Q/100 is more preferably 5.0 or less, still more preferably 4.0 or less, and particularly preferably 3.5 or less.

From the same viewpoint as described above, when a photosensitive resin layer having a thickness of 25 μm formed from the photosensitive resin composition of the present embodiment is formed on the surface of a substrate, and the photosensitive resin layer is exposed with an exposure amount of 1/10, which is an exposure amount in which the maximum residual film number when exposure is performed with a schleph 21-stage exposure scale as a mask and then development is performed is 6-stage,

the value of P '× Q/100 when the average number of the olefinic double bonds in the compound (C) is Q and the reaction rate of the olefinic double bonds in the compound (C) after the exposure is P' is preferably 0.3 or more. The exposure amount at this time is a value obtained in consideration of the exposure amount of the weakly exposed region. From the same viewpoint as above, the value of P' × Q/100 is more preferably 0.5 or more, more preferably 0.7 or more, still more preferably 1.0 or more, yet more preferably 1.3 or more, particularly preferably 1.6 or more, and most preferably 1.9 or more;

more preferably 5.0 or less, still more preferably 3.0 or less, and particularly preferably 2.5 or less.

When the transmittance at 405nm (h-ray) when the polyethylene film of the photosensitive resin laminate is peeled off is less than 65%, the value of P.times.Q/100 is measured under the exposure conditions of a direct drawing exposure machine using h-ray. When the transmittance at 405nm (h-ray) when the polyethylene film of the photosensitive resin laminate is peeled off is 65% or more, the value of P × Q/100 is measured under the exposure conditions of a direct drawing exposure machine using i-ray.

The value of P'. times.Q/100 can be measured under the exposure conditions of an exposure machine of an ultra-high pressure mercury lamp.

< photosensitive resin laminate >

The photosensitive resin composition of the present disclosure can be used to form a photosensitive resin laminate. Typically, the photosensitive resin laminate includes a support film and a photosensitive resin layer formed of the photosensitive resin composition and laminated on the support film. The photosensitive resin laminate may have a protective layer on the surface opposite to the supporting film side as necessary.

The supporting film is preferably a transparent film that transmits light emitted from the exposure light source. Examples of such a support film include: polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene film, polyacrylonitrile film, styrene copolymer film, polyamide film, cellulose derivative film, and the like. These films may be stretched as needed.

The haze of the support film is preferably 5 or less.

The support film is advantageously thin in terms of image formability and economy, and preferably 10 to 30 μm in view of the function of maintaining strength.

An important characteristic of the protective layer used for the photosensitive resin laminate is that it has an appropriate adhesive force. That is, the adhesion force of the protective layer to the photosensitive resin layer is preferably sufficiently smaller than the adhesion force of the support film to the photosensitive resin layer, and the protective layer can be easily peeled from the photosensitive resin laminate. Examples of the protective layer include a polyethylene film, a polypropylene film, and a film having excellent releasability disclosed in jp 59-202457 a.

The thickness of the protective layer is preferably 10 to 100 μm, and more preferably 10 to 50 μm.

The thickness of the photosensitive resin layer in the photosensitive resin laminate varies depending on the application, and is preferably 5 to 100 μm, and more preferably 7 to 60 μm. The thinner the thickness of the photosensitive resin layer is, the higher the resolution is, and the thicker the thickness is, the higher the film strength is.

< method for producing photosensitive resin laminate >

The photosensitive resin laminate can be produced by sequentially laminating a photosensitive resin layer and a protective layer, which is laminated as necessary, on a support film. As the method thereof, a known method can be employed. For example, a photosensitive resin composition used for the photosensitive resin layer is mixed with a solvent in which the composition is dissolved to prepare a uniform solution-like coating solution. Then, the coating liquid is applied onto a support film by using a bar coater or a roll coater, and then dried, whereby a photosensitive resin layer formed of a photosensitive resin composition can be laminated on the support film. Next, a protective layer is laminated on the photosensitive resin layer as necessary, whereby a photosensitive resin laminate can be produced.

< method for Forming Circuit Pattern >

Another embodiment of the present invention provides a method of forming a circuit pattern, including:

a step (laminating step) of forming a layer of the photosensitive resin composition of the present disclosure on a substrate;

a step (exposure step and development step) of exposing and developing the layer of the photosensitive resin composition to form a resist pattern; and

and a step (etching step or plating step) of etching or plating the substrate on which the resist pattern is formed. After the above-described series of steps, a peeling step of peeling the resist pattern from the laminate is preferably further provided.

In a preferred embodiment, the layer of the photosensitive resin composition is formed using the photosensitive resin laminate.

Next, an example of a method for forming a circuit pattern using the photosensitive resin laminate and the copper-clad laminate as a substrate will be described.

(1) Lamination process

The method comprises the following steps: while the protective layer of the photosensitive resin composition is peeled off, the composition is adhered to a substrate such as a copper-clad laminate or a flexible substrate using, for example, a hot roll laminator.

(2) Exposure Process

The method comprises the following steps: a step of exposing a mask film having a desired wiring pattern through the mask film in a state of being in close contact with a layer of a photosensitive resin composition formed on the substrate;

a step of exposing a desired wiring pattern by a direct imaging exposure method; or

And exposing the image of the photomask by an exposure method in which the image is projected through a lens. The photosensitive resin composition of the present embodiment is more remarkably advantageous in a direct imaging exposure method using direct drawing of a wiring pattern or an exposure method in which an image of a photomask is projected through a lens, and is particularly remarkably advantageous in a direct imaging exposure method.

(3) Developing process

The method comprises the following steps: after the exposure step, the support on the photosensitive resin layer is peeled off, and then the unexposed portion is developed and removed using a developer of an alkaline aqueous solution, thereby forming a resist pattern on the substrate.

As the alkaline aqueous solution, Na may be used₂CO₃Or K₂CO₃An aqueous solution of (a). The alkaline aqueous solution can be suitably selected according to the characteristics of the photosensitive resin layer, but preferably Na is used in a concentration of about 0.2 to 2 mass% and at about 20 to 40 ℃₂CO₃An aqueous solution.

Through the above steps, a resist pattern can be obtained. In some cases, the heating step may be performed at about 100 to 300 ℃ for 1 minute to 5 hours after these steps. By performing this heating step, the adhesion and chemical resistance of the resulting cured resist pattern can be further improved. For the heating in this case, for example, a heating furnace of a hot air, infrared ray or far infrared ray system can be used.

(4) Etching or plating process

The surface of the substrate exposed by the development (for example, the copper surface of the copper-clad laminate) is etched or plated to produce a conductor pattern.

The etching step is a step of: the resist pattern formed through the above steps is sprayed with an etching solution from above, and the copper surface not covered with the resist pattern is etched to form a desired circuit pattern. Examples of the etching method include acid etching and alkali etching, and the etching method can be performed by a method suitable for the photosensitive resin laminate used.

(5) Peeling step

Thereafter, the laminate is treated with an aqueous solution having an alkali stronger than that of the developer, and the resist pattern is peeled off from the substrate. The alkaline aqueous solution for stripping is not particularly limited. Usually, an aqueous solution of NaOH or KOH having a concentration of about 2 to 5% by mass and a temperature of about 40 to 70 ℃ is used. A small amount of a water-soluble solvent may be added to the stripping solution.

Examples

The present invention will be described more specifically with reference to examples and comparative examples.

First, a method of producing the evaluation samples of examples and comparative examples will be described, and then, the evaluation method and the evaluation result of the obtained samples will be described.

(1) Evaluation of alkali-soluble Polymer

< measurement of weight average molecular weight >

The weight average molecular weight of the polymer was determined as a polystyrene equivalent using a Gel Permeation Chromatograph (GPC) manufactured by japan spectrography. The apparatus constitution and the reagents used are as follows, respectively.

A pump: manufactured by Gulliver, type PU-1580

Column: shodex (registered trademark) KF-807, KF-806M, KF-806M and KF-802.5, manufactured by Showa Denko K.K., 4, were connected in series and used

Fluidized bed solvent: tetrahydrofuran (THF)

And (3) correcting a curve: a polystyrene standard sample (Shodex STANDARD SM-105, Showa Denko K.K.) was used to prepare

(2) Method for producing sample for evaluation

Evaluation samples of examples and comparative examples were prepared as follows.

< production of photosensitive resin laminate >

The components shown in table 1 below (wherein the numbers in the columns of the components indicate the amount of solid components (parts by mass)) and a solvent were sufficiently mixed by stirring to prepare a photosensitive resin composition liquid. The photosensitive resin composition liquid formulations of examples 1 to 19 and comparative examples 1 to 8 were added with the following components in addition to the components shown in Table 1:

0.05 parts by mass of diamond green as a coloring substance;

0.6 part by mass of leuco crystal violet as a leuco dye;

0.2 part by mass of a 1:1 (mass ratio) mixture of 1- (2-di-n-butylaminomethyl) -5-carboxybenzotriazole and 1- (2-di-n-butylaminomethyl) -6-carboxybenzotriazole as a benzotriazole compound;

0.05 part by mass of diglycidyl ether of hydrogenated bisphenol A as an antioxidant;

0.004 part by mass of an aluminum salt to which 3mol of nitrosophenylhydroxylamine was added as a radical polymerization inhibitor; and

2 parts by mass of p-toluenesulfonamide as a plasticizer.

0.7 parts by mass of tribromomethyl phenylsulfone as a halide was added to the photosensitive resin composition liquid except for comparative examples 1 and 2.

The photosensitive resin composition liquid formulations of examples 20 to 44 and comparative examples 9 to 12 were not compounded with the above additional components except for those described in Table 1.

All of the photosensitive resin composition solutions further contain a solvent introduced from an alkali-soluble polymer solution blended in the solution and a solvent added for adjusting the concentration.

Each of the prepared solutions was uniformly applied to the surface of a polyethylene terephthalate film (GR-16, manufactured by Teyer デュポンフィルム, Inc.) having a thickness of 16 μm as a support film by using a bar coater, and dried in a drier at 95 ℃ for 2.5 minutes to form a photosensitive resin composition layer. The dry thickness of the photosensitive resin composition layer was adjusted to 25 μm. Subsequently, a 19 μm-thick polyethylene film (GF-18, manufactured by タマポリ Co.) was attached as a protective layer to the surface of the photosensitive resin composition layer (the other surface of the polyethylene terephthalate film) to obtain a photosensitive resin laminate.

The names of the components shown in table 1 by abbreviation are shown in table 2 below.

< substrate surface conditioning >

A copper-clad laminate of 0.4mm thickness, in which a rolled copper foil of 35 μm thickness was laminated, was used as a substrate for evaluation of image quality, resist sag width, etching properties, and peeling time. The substrate was treated with CPE-900 (registered trademark, manufactured by Mitsubishi chemical corporation), and then treated with 10 mass% H₂SO₄The surface was cleaned and rinsed with pure water before use.

< lamination >

Various laminates for evaluation were obtained by laminating a copper-clad laminate preheated to 60 ℃ while surface conditioning the polyethylene film of the photosensitive resin laminate while peeling off the polyethylene film, at a roll temperature of 105 ℃ using a hot roll laminator (available from asahi chemical co., ltd., AL-700). The air pressure was set to 0.35MPa, and the lamination speed was set to 1.5 m/min.

For evaluation other than those described in particular in the evaluation methods described later, the laminated laminate was used to perform evaluation on samples prepared under the conditions described in the items of various evaluation methods. The general operation methods for exposure, development, etching, and peeling are as follows.

< Exposure >

For the following "(x) P' × Q/100"Extra exposure was performed with a Schmitt 21-level exposure scale or a predetermined mask pattern for DI exposure using a direct drawing exposure machine (DE-1 DH, manufactured by Hitachi ビアメカニクス Co., Ltd., light source: GaN blue-violet diode (dominant wavelength: 405. + -.5 nm)) at an illuminance of 80mW/cm²Exposure is performed under the conditions of (1). The exposure was performed with an exposure amount of 6 steps at the highest residual film number in the case of performing exposure and development using the schrader 21 exposure scale as a mask.

For a substrate for evaluating items other than the resist sag width, the position of the focal point at the time of exposure is made to coincide with the substrate surface,

for the substrate for evaluation of the sag width of the resist layer, the position of the focal point at the time of exposure was shifted from the substrate surface toward the substrate inner side in the thickness direction of the substrate by 200 μm.

< development >

After the polyethylene terephthalate film of the evaluation substrate exposed as described above was peeled off, Na having a concentration of 1% by mass and a temperature of 30 ℃ was adjusted by using an alkaline developing machine (a developing machine for dry film, manufactured by Fuji photo Co., Ltd.)₂CO₃After the aqueous solution was sprayed for a predetermined period of time, the photosensitive resin layer was washed with water by spraying pure water for a predetermined period of time to dissolve and remove the unexposed portion of the photosensitive resin layer, thereby producing a cured resist pattern.

The developing time and the water washing time were each set to 2 times the minimum developing time.

The minimum development time is the minimum time required for the photosensitive resin layer at the unexposed portion to be completely dissolved.

< etching >

For the evaluation substrate on which the cured resist pattern was formed by the above development, a cuprous chloride etching solution adjusted to 50 ℃ was sprayed over a period of time 1.3 times the shortest etching time using a cupric chloride etching apparatus (manufactured by tokyo chemical industries, ltd.) to dissolve and remove the copper foil not covered with the resist pattern on the copper-clad laminate.

The cuprous chloride etching solution is a solution with the concentration of cuprous chloride being 250g/L and the concentration of hydrochloric acid being 3 mol/L. The minimum etching time is a time required for the copper foil on the substrate to be completely dissolved and removed.

< peeling >

The cured resist pattern was peeled off from the evaluation substrate after the etching by spraying a 3 mass% aqueous solution of sodium hydroxide adjusted to a temperature of 50 ℃.

(3) Method for evaluating sample

Next, a method of evaluating a sample will be described.

(i) Evaluation of sensitivity

The substrate for sensitivity evaluation after 15 minutes from the lamination was exposed through a mask of a schmuth 21-stage exposure scale. Then, development was performed in a time 2 times the shortest development time.

The above operation was repeated while changing the exposure amount, and the exposure amount at the highest residual film level of 6 levels was investigated.

The exposure amounts of examples 1 to 19 and comparative examples 1 to 8 were classified by the following criteria so that the maximum residual film number was 6.

○ good exposure with the highest residual film grade of 6 grades less than 20mJ/cm²In the case of

× (bad), the exposure amount is 20mJ/cm when the highest residual film grade is 6 grades²The above situation

The values of the exposure amounts for examples 20 to 44 and comparative examples 9 to 12, in which the maximum residual film number was 6, are shown in Table 1. For the applications envisaged in these examples, when the exposure amount is 70mJ or less, the sensitivity is evaluated to be good, preferably 40mJ or less, more preferably 30mJ or less, and still more preferably 20mJ or less.

(ii) Evaluation of resolution (1)

The evaluation substrate after 15 minutes from the lamination was exposed to a pattern of lines and spaces with a width ratio of the exposed portion to the unexposed portion of 1: 1. Subsequently, development was performed for a development time 2 times the shortest development time to obtain a cured resist pattern. The minimum mask line width in the cured resist pattern where the line and space patterns were normally formed was investigated.

The values of the minimum mask line widths in examples 1 to 19 and comparative examples 1 to 8 were classified according to the following criteria.

O (good): the minimum mask line width is less than 25 μm

Δ (and lattice): the minimum mask line width is more than 25 μm and less than 30 μm

X (bad): the minimum mask line width value is greater than 30 μm

The values of the minimum mask line widths in examples 20 to 44 and comparative examples 9 to 12 are shown in table 1. For the applications envisaged in these examples, when the minimum mask line width is 60 μm or less, it can be evaluated that the resolution (1) is good, preferably 35 μm or less, more preferably 25 μm or less, still more preferably 20 μm or less, and particularly preferably 16 μm or less.

(iii) Evaluation of resolution (2)

In some examples and comparative examples, resolution evaluation of positive type release from independent mold (ポジ was independently removed け) was performed in addition to the resolution evaluation (1) of the above (ii).

That is, the unexposed portion of the evaluation substrate after 15 minutes from the lamination was exposed to a pattern in space. Subsequently, development was performed with a development time 2 times the shortest development time to obtain a cured resist pattern. At this time, the value of the minimum space width of the space where the unexposed portion is normally formed is set as the value of the resolution (positive type independent mold release).

When the minimum space width is 45 μm or less, it is evaluated that the resolution (2) is good, and it is preferably 35 μm or less, more preferably 30 μm or less, further preferably 25 μm or less, and particularly preferably 20 μm or less.

(iv) Evaluation of adhesion

The evaluation substrate after 15 minutes from the lamination was exposed to a pattern in which the exposed portion became a line. Subsequently, development was performed with a development time 2 times the shortest development time to obtain a cured resist pattern. The minimum mask line width where the cured resist line is normally formed was investigated.

The minimum mask line widths of examples 1 to 19 and comparative examples 1 to 8 were classified according to the following criteria.

O (good): the minimum mask line width is less than 25 μm

X (bad): the minimum mask line width value is greater than 30 μm

The values of the minimum mask line widths in examples 20 to 44 and comparative examples 9 to 12 are shown in table 1. For the applications envisaged in these examples, when the minimum mask line width is 70 μm or less, the adhesion is evaluated to be good, preferably 30 μm or less, more preferably 25 μm or less, still more preferably 20 μm or less, and particularly preferably 10 μm or less.

(v) Evaluation of resist skirt width

The evaluation substrate after 15 minutes from the lamination was exposed to a pattern of lines and spaces with a width ratio of the exposed portion to the unexposed portion of 1: 1. During exposure, the position of the focal point during exposure was shifted 200 μm from the substrate surface toward the substrate inner side in the thickness direction of the substrate. By this measure, the weak exposure region at the end of the exposure pattern is enlarged, and the size of the sag width of the resist layer is easily compared.

After the exposed substrate was developed with a developing time 2 times the shortest developing time, the exposed portion of the copper substrate of the substrate was soft-etched with 200g/L aqueous ammonium persulfate solution for 60 seconds to obtain a sample for evaluating the width of the resist sagging. The line pattern portion of the sample having a 1:1 ratio of L/S of 45 μm/45 μm was observed with a scanning electron microscope (S-3400N, manufactured by hitachi ハイテク), and the width of the runout portion of the line pattern was determined.

For examples 1 to 19 and comparative examples 1 to 8, the values were graded in terms of resist line width on the basis of the following criteria:

very good: the width of the resist skirt is 1.5 μm or less

O (good): the width of the resist skirt is more than 1.5 μm and less than 2.5 μm

Δ (and lattice): the width of the resist skirt is more than 2.5 μm and less than 3.5 μm

X (bad): the width of the resist skirt is larger than 3.5 μm

The resist sweep widths of examples 20 to 44 and comparative examples 9 to 12 are shown in Table 1. For the applications envisaged in these examples, when the value of the width of the resist sweep is 10 μm or less, it can be evaluated that the adhesion is good, preferably 3 μm or less, more preferably 2.5 μm or less, further preferably 2 μm or less, further preferably 1.5 μm or less, and particularly preferably 1 μm or less.

Please refer to fig. 1 for a method for measuring the width of the sag of the resist layer.

(vi) Evaluation of etching Property

The evaluation substrate after 15 minutes from the lamination was exposed to a pattern of lines and spaces with a width ratio of the exposed portion to the unexposed portion of 1: 1. The resist pattern was developed with a developing time 2 times the shortest developing time, etched with a time 1.3 times the minimum etching time, and then the cured resist pattern was peeled off with an aqueous sodium hydroxide solution, thereby obtaining a conductor pattern. The conductor pattern was observed with an optical microscope (MM-800, manufactured by nikon corporation) to examine the shape of the conductor pattern, and was classified according to the following criteria:

o (good): the conductor pattern was linearly formed, and the wave (wobbble) and the penetration of the etching solution were not observed

Δ (and lattice): the conductor pattern was linearly formed, but the penetration of the etching solution was slightly observed

X (bad): at least one of a case where the conductor pattern is not linearly formed and a case where the etching liquid is remarkably penetrated is observed.

(vii) Evaluation of foamability of developing solution

The above-mentioned<Production of photosensitive resin laminate>The photosensitive resin laminate prepared in (1) was cut into a size of 0.048m²The photosensitive resin layer after the protective layer and the support film were peeled off was immersed in 120ml of 1 mass% Na₂CO₃In the aqueous solution, a solution in which the resin layer is dissolved is obtained. Placing the solution into a gas absorption tank with a capacity of 500ml, and introducing6000 ml/min of nitrogen gas passed through a glass filter of G3 were bubbled. The time until the generated bubbles overflowed from the gas absorption tank was measured, and the results thereof were classified according to the following criteria.

Very good: no overflow condition in 100 seconds

O (good): overflow condition in more than 30 seconds and in 100 seconds

X (bad): overflow condition in 30 seconds

(viii) Pressure flow test (press flow test)

The photosensitive resin laminate produced in < production of photosensitive resin laminate > was cut into 2.5cm square, and after the protective layer was peeled off, the resultant was sandwiched between 10cm square polyethylene terephthalate films, and a force of 100kg was applied for 5 minutes by a press heated to 40 ℃. Thereafter, the width of the extrusion of the photosensitive resin layer was measured in 4 directions (8 positions in total), and the average value thereof was obtained. In this test, n is 2, and the average value of n 2 is obtained and used as the value of the pressure flow test.

It is empirically known that when this value is large, edge fusion tends to occur, and the substrate cannot be stably laminated substantially at the time of lamination.

(ix)P×Q/100

The transmittance at 405nm (h-ray) when the polyethylene film of the photosensitive resin laminate was peeled off was less than 65% in all of the examples and comparative examples. Therefore, the value of P.times.Q/100 was measured under the exposure conditions of a direct writing exposure machine using h-rays.

Using a direct drawing exposure apparatus (DE-1 DH, manufactured by Hitachi ビアメカニクス Co., Ltd., light source: GaN blue-violet diode (dominant wavelength: 405. + -.5 nm)), the film was formed from the above<Production of photosensitive resin laminate>The photosensitive resin laminate produced in (1) is subjected to direct image-forming exposure on the polyethylene terephthalate film (support layer) side. At this time, the position of the focal point at the time of exposure was made to coincide with the bottom of the resist layer. The illuminance at the time of exposure was set to 80mW/cm². The exposure amount at this time is the highest residual film when the exposure is performed by using the schrader 21 exposure scale as a mask and then the development is performed by the above methodThe number of stages is 6 stages of exposure (ordinary exposure).

The reaction rate P of the ethylenic double bond of the cured resist obtained in the above manner was determined by FT-IR (NiCOLET 380, Thermo SCIENTIFIC Co., Ltd.). The wave number was determined to be 810cm^-1The peak height below, this value being taken as the amount of olefinic double bonds.

The average number of the olefinic double bonds (number of functional groups) in the compound (C) was calculated, and this value was designated as Q. When the compound (C) is a mixture of a plurality of compounds, Q is determined in consideration of the content mass of each component.

The value of P.times.Q/100 was obtained from P and Q above.

(x)P’×Q/100

Using an ultra-high pressure mercury lamp (HMW-801, manufactured by オーク),from the foregoing<Production of photosensitive resin laminate Making>The photosensitive resin laminate produced in (1)The side of the polyethylene terephthalate film (support layer) is exposed. The exposure amount is as above<(ix)P×Q/100>The exposure amount of 1/10 (the decimal point is cut off or less) is used as the middle exposure amount. Otherwise, the reaction rate P' of the olefinic double bonds in the cured resist layer was determined by FT-IR in the same manner as described above at 1/10 exposure (slight exposure).

From this P 'value and the Q value calculated in the same manner as described above, the value of P' × Q/100 at the time of weak exposure was obtained.

(xi) Hue stability of photosensitive resin composition concoction liquid

The transmittance at 630nm of the photosensitive resin laminate was measured using an ultraviolet-visible light (UV-Vis) measuring device (U-3010 spectrophotometer, manufactured by hitachi ハイテクノロジーズ) as follows:

(i) the polyethylene film of the photosensitive resin laminate was peeled off, the transmittance at 630nm was measured, and the obtained value was defined as the initial transmittance (T)_in)。

(ii) A photosensitive resin laminate was produced using a photosensitive resin composition preparation after storage at 40 ℃ for 3 days, the transmittance at 630nm was measured by peeling off the polyethylene film of the photosensitive resin laminate, and the obtained value was taken as the transmittance after storage(T_af)。

The hue stability was obtained by the following equation:

T_af-T_in。

(xii) Stripping time

A rectangular pattern of 5cm X6 cm was exposed on the evaluation substrate 15 minutes after lamination. Subsequently, development was performed with a development time 2 times the shortest development time to obtain a cured resist pattern.

The cured resist pattern on the substrate obtained in this manner was immersed in a 2 mass% NaOH aqueous solution at 50 ℃ to measure the time until the resist was completely peeled from the substrate, and this was taken as the peeling time.

(xiii) Flexibility of cured film

The photosensitive resin laminate was laminated on NIKAFLEX F-30VC 125C 11/2 (manufactured by ニッカン industries, Ltd.) to expose a pattern having a width of 2.5cm and a length of 30 cm. Next, development was performed with a development time 2 times the shortest development time to prepare a long sample.

They were respectively hung on SUS rods having diameters of 1,2,3, 4,5 and 6mm phi in such a manner that the substrate side was in contact with the SUS rods. Then, both ends of the long sample were held so that the bending angle became 90 degrees, and the long sample was wrinkled back and forth 10 times.

At this time, the diameter of the largest SUS rod in which cracks did not appear on the resist surface was examined and classified as follows.

O (good): no crack at 4mm phi

Δ (and lattice): cracks appeared at 4mm phi, but not at 5mm phi

(xiiv) support film puncture elongation Properties

A photosensitive resin laminate was laminated on both sides of a substrate formed of a 1.6mm thick copper-clad laminate having an opening with a diameter of 6mm, and the entire surface of each side was exposed. Next, development was performed with a development time 2 times the shortest development time, thereby obtaining a cured resist pattern.

Then, the puncture strength and elongation of the film at the opening portion of the substrate were measured by Tencel (manufactured by オリエンテック, RTM-500) using a cylinder having an insertion diameter of 1.5 mm.

(3) Evaluation results

The evaluation results of the examples and comparative examples are shown in table 1.

Table 2 shows names of the respective components indicated by short names in table 1. All of the alkali-soluble polymers shown in table 2 were blended in the form of a methyl ethyl ketone solution having the solid content concentration shown in the table. The abbreviations in the columns of the types of functional groups in the compounds having an ethylenic double bond in Table 2 are as follows, respectively.

A: acrylate radical

MA: methacrylate group

Table 3 shows the glass transition temperatures (literature values) when the respective monomers used for synthesizing the alkali-soluble resin were each made into a homopolymer.

[ Table 1]

Table 1 (the 1 st of 11 tables)

(Table 1 with the following)

[ Table 2]

Table 1 (2 nd table of 11 tables in total)

(Table 1 with the following)

[ Table 3]

Table 1 (the 3 rd table of 11 tables in total)

(Table 1 with the following)

[ Table 4]

Table 1 (4 th of 11 tables)

(Table 1 with the following)

[ Table 5]

Table 1 (the 5 th of 11 tables in total)

(Table 1 with the following)

[ Table 6]

Table 1 (6 th of 11 tables)

(Table 1 with the following)

[ Table 7]

Table 1 (7 th of 11 tables in total)

(Table 1 with the following)

[ Table 8]

Table 1 (8 th of 11 tables)

(Table 1 with the following)

[ Table 9]

Table 1 (9 th of 11 tables in total)

(Table 1 with the following)

[ Table 10]

[ Table 11]

[ Table 12]

[ Table 13]

Table 2 (2 nd table of 4 tables)

(Table 2 with the following)

[ Table 14]

[ Table 15]

Table 2 (4 th of the total 4 tables)

(end of Table 2)

[ Table 16]

Industrial applicability

The photosensitive resin composition of the present embodiment, and the photosensitive resin laminate, resist pattern, and circuit pattern produced using the same can be suitably used for production of printed wiring boards and flexible printed wiring boards; semiconductor packages such as lead frames for mounting IC chips, metal masks, BGA, CSP, and the like; tape substrates such as TAB and COF, semiconductor bumps, ITO electrodes, address electrodes, electromagnetic wave shields, and the like.

Claims

1. A photosensitive resin composition, comprising:

(A) alkali-soluble polymer: 40 to 80 mass%,

(B) Photopolymerization initiator: 0.1 to 20 mass%, and

(C) compound having an ethylenic double bond: 5 to 50% by mass of a binder,

the photosensitive resin composition is used for direct imaging exposure.

2. The photosensitive resin composition according to claim 1, wherein a photosensitive resin layer having a thickness of 25 μm and formed from the photosensitive resin composition is formed on a substrate surface, and when the photosensitive resin layer is exposed with an exposure amount in which the maximum residual film number in the case of exposure using a Schonfish 21-stage exposure scale as a mask and then development is performed is 6 stages,

a value of PxQ/100 is 0.7 or more, where Q is an average number of the olefinic double bonds in the compound (C) and P is a reaction rate of the olefinic double bonds in the compound (C) after the exposure.

3. The photosensitive resin composition according to claim 1 or 2, wherein a photosensitive resin layer having a thickness of 25 μm formed from the photosensitive resin composition is formed on a surface of a substrate, and when the photosensitive resin layer is exposed with an exposure amount of 1/10, which is an exposure amount in which the maximum residual film number in the case of exposure using a Schonfier 21-stage exposure scale as a mask and then development is performed is 6,

4. The photosensitive resin composition according to any one of claims 1 to 3, wherein the weight average Tg of the alkali-soluble polymer (A) is^totalIs 30 ℃ or higher and 125 ℃ or lower.

5. The photosensitive resin composition according to any one of claims 1 to 4, wherein the compound (C) comprises a compound having 3 or more methacryloyl groups in one molecule.

6. The photosensitive resin composition according to any one of claims 1 to 5, wherein the compound (C) comprises a compound having 4 or more methacryloyl groups in one molecule.

7. The photosensitive resin composition according to any one of claims 1 to 6, wherein the compound (C) comprises a compound represented by the following general formula (IV):

in the formula (IV), n₁、n₂、n₃And n₄Each independently represents an integer of 1 to 25, n₁+n₂+n₃+n₄Is an integer of 9 to 60, and,

R₅、R₆、R₇and R₈Each independently represents an alkylene group, R₅、R₆、R₇And R₈When there are plural R's, respectively₅、R₆、R₇And R₈The same or different.

8. The photosensitive resin composition according to claim 7, wherein in the general formula (IV), n₁+n₂+n₃+n₄Is an integer of 15 to 40.

9. The photosensitive resin composition according to claim 7, wherein in the formula (IV), n is₁+n₂+n₃+n₄Is an integer of 15 to 28.

10. The photosensitive resin composition according to any one of claims 1 to 9, wherein the photopolymerization initiator (B) comprises an acridine compound.

11. The photosensitive resin composition according to any one of claims 1 to 10, further comprising a halide.

12. The photosensitive resin composition according to any one of claims 1 to 11, wherein the photopolymerization initiator (B) comprises N-phenylglycine or a derivative thereof.

13. The photosensitive resin composition according to any one of claims 1 to 12, wherein the alkali-soluble polymer (a) has an aromatic hydrocarbon group.

14. A photosensitive resin composition, characterized in that the photosensitive resin composition contains:

(A) alkali-soluble polymer: 40 to 80% by mass of a binder,

(B) photopolymerization initiator: 0.1 to 20 mass%, and

(C) compound having an ethylenic double bond: 5 to 50% by mass of a binder,

15. The photosensitive resin composition according to claim 14, wherein a photosensitive resin layer having a thickness of 25 μm formed from the photosensitive resin composition is formed on a substrate surface, and when the photosensitive resin layer is exposed with an exposure amount in which the maximum residual film number in the case of exposure using a Schonfish 21-stage exposure scale as a mask and then development is performed is 6 stages,

16. The photosensitive resin composition according to claim 14 or 15, wherein a photosensitive resin layer having a thickness of 25 μm formed from the photosensitive resin composition is formed on a surface of a substrate, and when the photosensitive resin layer is exposed with an exposure amount of 1/10, which is an exposure amount in which the maximum residual film number in the case of exposure using a Schonfier 21-stage exposure scale as a mask and then development is performed is 6,

17. The photosensitive resin composition according to any one of claims 14 to 16, wherein the compound (C) comprises a compound having 4 or more methacryloyl groups in one molecule.

18. The photosensitive resin composition according to any one of claims 14 to 17, wherein the compound (C) comprises a compound represented by the following general formula (IV):

R₅、R₆、R₇to therebyAnd R₈Each independently represents an alkylene group, R₅、R₆、R₇And R₈When there are plural R's, respectively₅、R₆、R₇And R₈The same or different.

19. The photosensitive resin composition according to claim 18, wherein in the formula (IV), n is₁+n₂+n₃+n₄Is an integer of 15 to 40.

20. The photosensitive resin composition according to claim 18, wherein in the formula (IV), n is₁+n₂+n₃+n₄Is an integer of 15 to 28.

21. The photosensitive resin composition according to any one of claims 14 to 20, wherein the photopolymerization initiator (B) comprises an acridine compound.

22. The photosensitive resin composition according to any one of claims 14 to 21, further comprising a halide.

23. The photosensitive resin composition according to any one of claims 14 to 22, wherein the photopolymerization initiator (B) comprises N-phenylglycine or a derivative thereof.

24. The photosensitive resin composition according to any one of claims 14 to 23, wherein the alkali-soluble polymer (a) has an aromatic hydrocarbon group.

25. The photosensitive resin composition according to any one of claims 14 to 24, wherein the weight average value Tg of the alkali-soluble polymer (a) is^totalIs 30 ℃ or higher and 125 ℃ or lower.

26. The photosensitive resin composition according to any one of claims 14 to 25, which is used for direct image-wise exposure.

27. A method of forming a circuit pattern, comprising:

a step of forming a layer of the photosensitive resin composition according to any one of claims 1 to 26 on a substrate;

and etching or plating the substrate on which the resist pattern is formed.

28. The method of claim 27, wherein the exposing is performed by direct imaging exposure.