阅读说明：本技术 感光性树脂组合物以及电路图案的形成方法 (Photosensitive resin composition and method for forming circuit pattern ) 是由 内藤一也 松田隆之 于 2015-05-21 设计创作，主要内容包括：提供感光性树脂组合物以及电路图案的形成方法。一种感光性树脂组合物,其特征在于,其含有：(A)碱溶性高分子：40～80质量％、(B)光聚合引发剂：0.1～20质量％、以及(C)具有烯属双键的化合物：5～50质量％,在基板表面上形成由该感光性树脂组合物形成的厚度25μm的感光性树脂层,在将曝光时的焦点的位置从基板表面沿该基板的厚度方向向基板内侧移动200μm的条件下进行曝光和显影而得到的抗蚀图案的抗蚀层下摆宽度为0.01μm～3.5μm,而且,前述感光性树脂组合物用于直接成像曝光。(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.)

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 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,

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. 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,

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. 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,

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

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,

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.

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,

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.

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):

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,

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

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;

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

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.

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,

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.

[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,

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.

[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):

{ 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 }.

[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,

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.

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

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).