JP2003021897A - Photosensitive resin composition and circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition capable of retaining suitability to patterning excellent in both sensitivity and resolution even when the amount of a photosensitive agent blended is reduced so as to obtain a light- colored polyimide resin film after imidation and to provide a circuit board with an insulating film obtained from the photosensitive resin composition. SOLUTION: The photosensitive resin composition 2 contains a polyamic acid resin and 5-10 pts.wt. 1,4-dihydropyridine derivative and carboxylic acid derivative based on 100 pts.wt. polyamic acid resin. The composition 2 is capable of forming a good negative type pattern film with a high residual film rate and high resolution in a range in which transparency is retained without using a large quantity of the photosensitive agent that colors the film. The circuit board with an insulating film obtained from the photosensitive resin composition is effectively used as a high reliability circuit board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition and a circuit board, and more specifically, a photosensitive resin composition suitably used for forming an insulating layer of the circuit board, and the photosensitive resin composition. The present invention relates to a circuit board having an insulating layer obtained from a product.

[0002]

2. Description of the Related Art Photosensitive polyamic acid resins containing a 1,4-dihydropyridine derivative as a photosensitizer are disclosed, for example, in JP-A-6-75376 and JP-A-7-2710.
34, Japanese Patent Laid-Open No. 10-39510, and the like. Such a photosensitive polyamic acid resin,
By coating the base material, irradiating it with an actinic ray through a predetermined photomask, exposing and developing it, and then imidizing it by heating, a film of a predetermined pattern made of a polyimide resin can be formed. .

A photosensitive polyamic acid resin containing such a 1,4-dihydropyridine derivative as a photosensitizer has excellent sensitivity and resolution, and a film obtained as a predetermined pattern also has high heat resistance. It is used for forming insulating layers such as an insulating layer and a surface protective layer (insulating protective layer).

[0004]

However, Japanese Patent Laid-Open No. 6-7.
The photosensitive polyamic acid resin containing a 1,4-dihydropyridine derivative as a photosensitizer described in JP-A-5376 and JP-A-7-271034 is finally 30
Since the film after imidization at 0 ° C or higher becomes a dark color (blackish brown), for example, when it is used as a surface protection layer of a circuit board, the conductor circuit portion below the surface protection layer is dark due to the dark color. However, there is a problem that it is difficult to inspect the appearance of the conductor circuit, and a higher transparency is desired.

Therefore, as a method of increasing the transparency, a method of reducing the blending amount of the photosensitizer can be considered. However, when the blending amount of the photosensitizer is reduced, the residual film rate becomes low, and high sensitivity and high resolution are obtained. This causes a problem that a pattern cannot be formed.

The present invention has been made in view of such circumstances, and an object thereof is to obtain a film of a light-colored polyimide resin after imidization, even if the compounding amount of the photosensitizer is reduced. It is an object of the present invention to provide a circuit board having a photosensitive resin composition capable of maintaining excellent patterning properties in both sensitivity and resolution, and an insulating layer obtained from the photosensitive resin composition.

[0007]

In order to achieve the above object, the photosensitive resin composition of the present invention comprises a polyamic acid resin and 5 to 100 parts by weight of the polyamic acid resin.
It is characterized by containing 10 parts by weight of a 1,4-dihydropyridine derivative and a carboxylic acid derivative represented by the following general formula (1).

[0008]

[Chemical 2] (In the formula, R represents an organic group, and n represents a number of 1 to 6.) The photosensitive resin composition of the present invention has the above general formula (100 parts by weight) with respect to 100 parts by weight of the polyamic acid resin. It is preferable to contain 5 to 40 parts by weight of the carboxylic acid derivative represented by 1).

In the photosensitive resin composition of the present invention, the carboxylic acid derivative represented by the general formula (1) is preferably at least one of pyromellitic acid, isophthalic acid and succinic acid.

Further, the present invention is a circuit board having an insulating layer obtained from these photosensitive resin compositions, and
It also includes a circuit board having a surface protective layer obtained from these photosensitive resin compositions.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive resin composition of the present invention comprises a polyamic acid resin, 5 to 10 parts by weight of a 1,4-dihydropyridine derivative based on 100 parts by weight of the polyamic acid resin, and the following general formula ( And a carboxylic acid derivative represented by 1).

[0012]

[Chemical 3] (In the formula, R represents an organic group, and n represents a number of 1 to 6.) The polyamic acid resin used in the present invention is a precursor of a polyimide resin and is not particularly limited, but usually, It has a repeating unit structure represented by the following general formula (2), and its weight average molecular weight is, for example, 5,000 to 200,000.
The degree is about 10,000 to 100,000.

[0013]

[Chemical 4] (In the formula, Ra represents a divalent organic group and Rb represents a tetravalent organic group.) In the formula (2), the tetravalent organic group represented by Rb is, for example, benzene, Naphthalene, perylene, diphenyl, diphenyl ether, diphenyl sulfone, diphenylpropane, diphenylhexafluoropropane,
Examples thereof include aromatic, araliphatic, aliphatic, and alicyclic tetravalent organic groups having a skeleton such as benzophenone, butane, and cyclobutane. Preferred are tetravalent organic groups having a skeleton of benzene, diphenyl, diphenylhexafluoropropane and benzophenone. In addition, these tetravalent organic groups may be only one kind, or may be two or more kinds.

In the above formula (2), 2 represented by Ra
Examples of the valent organic group include a skeleton such as diphenyl ether, benzophenone, diphenylmethane, diphenylpropane, diphenylhexafluoropropane, diphenyl sulfoxide, diphenyl sulfone, diphenyl, benzene, and diphenoxybenzene, aromatic, araliphatic, and aliphatic. And divalent organic groups of group and alicyclic. Preferably, diphenyl ether, benzene,
A divalent organic group having a skeleton of diphenoxybenzene can be mentioned. Note that these divalent organic groups may be only one type, or may be two or more types.

More specifically, such a polyamic acid resin can be obtained by reacting an organic tetracarboxylic dianhydride with a diamine. Examples of the organic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, and 2,2-bis (2,3-dicarboxyphenyl). ) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoro Propane dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfonic acid Examples thereof include dianhydride. Further, they may be used alone or in combination of two or more kinds.

As the diamine, for example, m-phenylenediamine, p-phenylenediamine, 3,4 '
-Diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,2
-Bis (4-aminophenoxyphenyl) propane,
2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy)
Benzene, 2,4-diaminotoluene, 2,6-diaminotoluene, diaminodiphenylmethane, 4,4'-diamino-2,2-dimethylbiphenyl, 2,2-bis (trifluoromethyl) -4,4'-diamino Examples thereof include biphenyl and oxydianiline. Further, they may be used alone or in combination of two or more kinds.

In the polyamic acid resin, the organic tetracarboxylic dianhydride and the diamine are mixed in a suitable organic solvent such as N-methyl-2-pyrrolidone at a ratio such that they are substantially equimolar. , N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide and the like, usually at 0 to 90 ° C. for 1 to 48 hours to obtain a polyamic acid resin solution. Good.

The 1,4-dihydropyridine derivative used in the present invention is represented by the following general formula (3).

[0019]

[Chemical 5] (In the formula, Ar represents an aromatic group having a nitro group at the ortho position, R1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R2, R3, R4 and R5 represent a hydrogen atom or a carbon atom. The alkyl groups of the formulas 1 to 4 are shown.) In the above formula (3), the aromatic group having a nitro group at the ortho position represented by Ar is preferably an o-nitrophenyl group, and R1 is The hydrogen atom or the alkyl group having 1 to 5 carbon atoms shown is preferably a methyl group, an ethyl group or a propyl group, and R2, R3, R
The hydrogen atom represented by 4 and R5 or the alkyl group having 1 to 4 carbon atoms is preferably a hydrogen atom, a methyl group,
An ethyl group may be mentioned. Particularly, hydrogen atoms are preferable as R2 and R3.

More specific examples of such 1,4-dihydropyridine derivative include, for example, 1-ethyl-3,5-
Dimethoxycarbonyl-4- (2-nitrophenyl)-
1,4-dihydropyridine, 1-methyl-3,5-dimethoxycarbonyl-4- (2-nitrophenyl) -1,
4-dihydropyridine, 1-propyl-3,5-dimethoxycarbonyl-4- (2-nitrophenyl) -1,4
-Dihydropyridine, 1-propyl-3,5-diethoxycarbonyl-4- (2-nitrophenyl) -1,4-
Dihydropyridine may be mentioned. Among these 1,4-dihydropyridine derivatives, 1-ethyl-3,5-dimethoxycarbonyl-4- represented by the following formula (4)
(2-Nitrophenyl) -1,4-dihydropyridine is preferred.

[0021]

[Chemical 6] Such a 1,4-dihydropyridine derivative can be obtained, for example, by substituting a substituted benzaldehyde, a double molar amount of an alkylpropiolate (a propargyl acid alkyl ester) and a corresponding primary amine in glacial acetic acid under reflux. It can be obtained by reacting. (Khim. Ge
terotsikl. Soed. , Pp. 1067-1
071,1982) In the present invention, the 1,4-dihydropyridine derivative is
It is compounded in the range of 5 to 10 parts by weight with respect to 100 parts by weight of the polyamic acid resin. If the amount is less than this,
When the resulting photosensitive resin composition is irradiated with an actinic ray, the effect of reducing the solubility of an exposed portion in an alkaline developer is poor and the formed pattern becomes unclear. On the other hand, if the blending amount is more than this, the transparency of the obtained film (film) cannot be obtained.

The carboxylic acid derivative used in the present invention is
It is represented by the following general formula (1).

[0023]

[Chemical 7] (In the formula, R represents an organic group, and n represents a number of 1 to 6.) In the above formula (1), examples of the organic group represented by R include benzene and C 1 to C 6. Examples thereof include aromatic, araliphatic, aliphatic, and alicyclic organic groups having a skeleton such as alkyl. It should be noted that these organic groups may be only one kind, or may be two or more kinds. Moreover, in said Formula (1), n is 1-6, Preferably it is 2-4.

By blending such a carboxylic acid derivative, the solubility of the non-exposed portion when the photosensitive resin composition of the present invention is irradiated with an actinic ray with an alkaline developer is increased, and the residual film rate is increased. Can be raised. this is,
This can be achieved by uniformly dissolving the carboxylic acid derivative in the film obtained by coating and drying the solution of the photosensitive resin composition. In addition, a carboxylic acid derivative having more carboxyl groups is expected to have a high effect of increasing the residual film rate, and in order to secure the elongation of the film at the time of film formation, it is preferable that the compounding part is as small as possible. .

From these viewpoints, more specific examples of the carboxylic acid derivative include pyromellitic acid, trimellitic acid, phthalic acid (isophthalic acid, terephthalic acid, orthophthalic acid), succinic acid, etc. Examples include pyromellitic acid, isophthalic acid, and succinic acid. Of these, pyromellitic acid having a low molecular weight and having four carboxyl groups is particularly preferable.

In the present invention, the carboxylic acid derivative is usually used in an amount of 5 to 4 with respect to 100 parts by weight of the polyamic acid resin.
The amount is 0 parts by weight, preferably 5 to 10 parts by weight. If the blending amount is less than this, the effect of increasing the residual film rate may be small, while if the blending amount is more than this,
In some cases, the carboxylic acid derivative is deposited in excess of the solubility limit in the polyamic acid resin, and the characteristics of the film obtained after imidization deteriorate.

Then, the photosensitive resin composition of the present invention is prepared, for example, by preparing a solution of the polyamic acid resin as described above, and then adding the 1,4-dihydropyridine derivative and the carboxylic acid derivative at the ratios described above. It can be easily obtained by mixing and dissolving.

The photosensitive resin composition of the present invention thus obtained is coated on a predetermined substrate, dried, and then irradiated with an actinic ray through a photomask having a predetermined shape and heated ( By heating after exposure), it is possible to form a negative latent image, and by developing this latent image, high sensitivity and high resolution can be obtained with a smaller compounding amount of the developer than before.
Moreover, it can be formed as a film of a good negative type pattern with little film loss.

By imidizing this by heating, it is possible to obtain a light-colored film that retains transparency, and is excellent in heat resistance, electrical characteristics, mechanical characteristics and adhesion to a substrate. It can be formed as a film of a polyimide resin. Therefore, such a photosensitive resin composition of the present invention is used as a material for forming an insulating layer such as an interlayer insulating layer or a surface protective layer used for insulating or protecting a solid element or a circuit board in the semiconductor industry. It can be preferably used.

Next, a method for forming an insulating layer of a circuit board using the photosensitive resin composition of the present invention will be described.

In this method, as shown in FIG.
First, a predetermined base material 1 is prepared, and as shown in FIG. 1 (b), the photosensitive resin composition 2 is applied onto the base material 1 and then heated and dried by hot air drying or the like. The solvent is removed from the photosensitive resin composition 2 to form a film.

The base material 1 is, for example, a foil or plate of a metal or alloy such as copper, aluminum, stainless steel, copper-beryllium, phosphor bronze, iron-nickel, etc., for example, a film of plastic such as polyimide resin or polyester resin. Is mentioned.

The photosensitive resin composition 2 may be coated by a known coating method such as a spin coater or a bar coater, and is appropriately suitable depending on the shape of the substrate 1 and the thickness of the coating. It may be applied according to the method. Further, it is preferable that the coating is performed so that the thickness after drying is 0.1 to 50 μm, preferably 1 to 30 μm. The adhesion can be improved by pre-coating the surface of the substrate 1 with a silane coupling agent or a titanate coupling agent before coating.

The drying is usually 40 ° C to 150 ° C.
To do. If it is lower than 40 ° C, the removal rate of the solvent is slow,
Further, if the temperature is higher than 150 ° C, imidization of the polyamic acid resin may start. Suitably 60 to 100 ° C
At.

Next, as shown in FIG. 1 (c), the dried photosensitive resin composition 2 is exposed by irradiating it with an actinic ray through a photomask 3, and then, if necessary, heated. A negative latent image is formed, and
As shown in (d), this is developed to form a negative image, that is, a film having a predetermined pattern.

Ultraviolet rays are preferably used as the actinic rays,
The exposure wavelength is 300 to 450 nm, and further 35
It is preferably 0 to 420 nm, and the integrated light amount of exposure is 100 to 5000 mJ / cm ² , and further 20.
It is preferably 0 to 3000 mJ / cm ² . After exposure, heat at about 140 ° C or higher (post-exposure heating)
Preferably. By performing the post-exposure heating at about 140 ° C. or higher, the solubility of the exposed portion in the developing solution containing an alkaline aqueous solution can be reduced, and a negative type image can be favorably formed in the next development.

Then, the developing treatment may be carried out by a known method such as a dipping method or a spraying method, and a developing temperature of 25 to 50 ° C. is usually suitable.
Examples of the developer to be used include organic alkaline aqueous solutions such as tetramethylammonium hydroxide and inorganic alkaline aqueous solutions such as sodium hydroxide and potassium hydroxide. The alkali concentration is usually in the range of 2 to 5% by weight, and if necessary, the alkaline aqueous solution may contain methanol, ethanol,
Lower aliphatic alcohols such as n-propanol and isopropyl alcohol may be added. The amount of such alcohol added is usually 50% by weight or less.

Then, after development, by washing with water,
A film of the photosensitive resin composition 2 (polyamic acid resin) having a predetermined pattern can be obtained.

In such exposure and development, the photosensitive resin composition 2 of the present invention contains a carboxylic acid derivative, so that even if the amount of the photosensitizer is small, the pattern can be obtained with excellent sensitivity and resolution. Can be trained.

Then, as shown in FIG. 1 (e), the insulating layer 4 made of a polyimide resin can be obtained by curing the film of the photosensitive resin composition 2 thus formed in a predetermined pattern. it can. The curing may be carried out by a known method, and for example, it is preferable to heat at about 350 to 500 ° C. for several hours under vacuum or in an inert gas atmosphere. As a result, the polyamic acid resin is imidized to form the insulating layer 4 of the film made of the polyimide resin.

For use as a circuit board, for example, as shown in FIG. 2A, the insulating layer 4 is used as the base layer 4, and the conductor layer 5 is formed on the base layer 4.
Are formed into a predetermined circuit pattern by a known patterning method such as a subtractive method, an additive method, a semi-additive method, and then, as shown in FIG.
As shown in (b), if necessary, the conductor layer 5 may be covered with a surface protective layer 6 made of an insulating layer. In addition, as a conductor for forming the conductor layer 5, for example,
Copper, nickel, gold, solder, or alloys thereof are used, and the thickness thereof is usually 1 to 15 μm. Further, as the surface protection layer 6, a polyimide resin formed from the photosensitive resin composition of the present invention may be used. The thickness of the surface protective layer 6 is usually 2 to 25 μm. Note that, depending on the use and the like, other known resins that are commonly used as the surface protective layer 6 may be used.

The base layer 4 of the circuit board thus obtained is excellent in heat resistance, electrical characteristics and mechanical characteristics, and further has good adhesion to the base material 1, and the surface protective layer 6 is When the compounding amount of the photosensitizer of the photosensitive resin composition 2 is 10 parts by weight or less relative to 100 parts by weight of polyamic acid, a light-colored film can be obtained even if it is heated and cured at 300 ° C. or higher, so that surface protection is achieved. The appearance of the circuit pattern of the conductor layer 5 in the layer 6 can be easily observed, the inspection is facilitated, and therefore, the circuit board can be effectively used as a highly reliable circuit board.

More specifically, in such a circuit board, more specifically, as shown in FIG. 3A, a conductor layer 5 made of copper foil or the like is provided on an insulating layer 4 made of polyimide resin, for example. A two-layer base material 7 that is directly laminated is prepared, and the conductor layer 4 of the two-layer base material 7 is
After forming a predetermined circuit pattern by a subtractive method or the like, as shown in FIG. 3 (c), the photosensitive resin composition of the present invention is applied onto the conductor layer 5 having the predetermined circuit pattern. After forming the film, similarly to the above, patterning is performed by exposure and development of actinic rays, and then curing is performed to form the surface protective layer 6 made of a polyimide resin having a predetermined opening portion 8. Then, an electrode may be formed on the conductor layer 5 exposed at the opening 8 by plating or the like.

It is to be noted that such a circuit board can be manufactured not only by using a two-layer base material but also by a widely known base material, for example, an insulating layer made of polyimide resin or the like. Alternatively, a three-layer base material in which a conductor layer made of copper foil or the like is laminated via an adhesive layer may be used.

Further, in such a circuit board, more concretely, for example, if the surface protective layer of the interposer for mounting a semiconductor element is formed by using the photosensitive resin composition of the present invention, the reliability is improved. It can be effectively used as an interposer for mounting high semiconductor elements.

[0046]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to the Examples and Comparative Examples.

Example 1 1 mol of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 0.85 mol of p-phenylenediamine,
0.14 mol of 4,4'-oxydianiline was dissolved in N-methyl-2-pyrrolidone (NMP) so that the total concentration of the monomers would be 14% by weight, and the mixture was allowed to stand at room temperature for 4 hours.
Further, the mixture was heated to 65 ° C. and reacted for 72 hours to obtain a solution of polyamic acid resin.

In this solution, 1-ethyl-3,5-dimethoxycarbonyl-4- (2-nitrophenyl) -1,1,3-ethyl-5,5-dimethoxycarbonyl-4-, was added to 100 parts by weight of the polyamic acid resin (solid content).
4-dihydropyridine 10 parts by weight and pyromellitic acid 5
And parts by weight were added and uniformly dissolved by stirring to obtain a solution of the photosensitive resin composition.

A solution of this photosensitive resin composition was prepared to a thickness of 25.
A spin coater was used to apply a coating on a stainless steel foil (SUS304) having a thickness of μm so that the thickness of the coating after drying was 25 μm, and the coating was formed by heating and drying at 90 ° C. for 15 minutes.

Next, the exposure amount 70 is passed through the photomask.
Ultraviolet rays at 0 mJ / cm ² (wavelength λ = 350 to 420 n
m) was exposed to light, heated at 180 ° C. for 10 minutes in an oven with a circulating hot air and then exposed to heat, and a 5 wt% solution of tetramethylammonium hydroxide (water: Ekinene = 1:
A negative image was formed by developing the image in 1) at 45 ° C. The residual film rate was 60%, and the developing time was 40 minutes.

The residual film ratio is the ratio of the film thickness of the polyamic acid resin immediately after development to the film thickness of the polyamic acid resin immediately after heating after exposure.

Then, the film was made of a polyimide resin by imidizing the polyamic acid resin by heating at 385 ° C. under a reduced pressure of 1.33 Pa. The obtained film had a thickness of 10 μm and was not colored so much that the underlying SUS foil was fully transparent and visible.

Example 2 The same solution of the polyamic acid resin as in Example 1 was used, and 1-ethyl-3,5-dimethoxycarbonyl-4 was added to this solution based on 100 parts by weight of the polyamic acid resin (solid content). 10 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine and 10 parts by weight of pyromellitic acid were added and uniformly dissolved by stirring to obtain a solution of a photosensitive resin composition.

Then, in the same manner as in Example 1, a negative pattern film of a polyamic acid resin was formed on the SUS foil. The residual film rate was 56%, and the developing time was 20 minutes.

Further, similarly to Example 1, imidization was performed at 385 ° C. to form a film made of a polyimide resin. The obtained film had a thickness of 10 μm and was not colored so much that the underlying SUS foil was sufficiently transparent.

Example 3 The same solution of the polyamic acid resin as in Example 1 was used, and 1-ethyl-3,5-dimethoxycarbonyl-4 was added to this solution based on 100 parts by weight of the polyamic acid resin (solid content). 5 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine and 10 parts by weight of isophthalic acid were added and uniformly dissolved by stirring to obtain a solution of a photosensitive resin composition.

Then, in the same manner as in Example 1, a negative pattern film of polyamic acid resin was formed on the SUS foil. The residual film rate was 71%, and the developing time was 43 minutes.

Further, as in Example 1, imidization was performed at 385 ° C. to form a film made of a polyimide resin. The obtained film had a thickness of 10 μm and was not colored so much that the underlying SUS foil was sufficiently transparent.

Example 4 The same solution of the polyamic acid resin as in Example 1 was used, and 1-ethyl-3,5-dimethoxycarbonyl-4 was added to 100 parts by weight of the polyamic acid resin (solid content). 5 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine and 10 parts by weight of succinic acid were added and uniformly dissolved by stirring to obtain a solution of a photosensitive resin composition.

Thereafter, in the same manner as in Example 1, a negative type pattern film of polyamic acid resin was formed on the SUS foil. The residual film rate was 51%, and the developing time was 84 minutes.

Further, similarly to Example 1, imidization was performed at 385 ° C. to form a film made of a polyimide resin. The obtained film had a thickness of 10 μm and was not colored so much that the underlying SUS foil was sufficiently transparent.

Comparative Example 1 The same solution of the polyamic acid resin as in Example 1 was used. In this solution, 1-ethyl-3,5-dimethoxycarbonyl-4 was added to 100 parts by weight of the polyamic acid resin (solid content). 15 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine was added and uniformly dissolved by stirring to obtain a solution of a photosensitive resin composition containing no carboxylic acid derivative.

Thereafter, a negative type pattern film of polyamic acid resin is formed on the SUS foil in the same manner as in Example 1, and imidization is performed at 385 ° C. in the same manner as in Example 1 to form a polyimide resin. A film was formed. The thickness of the obtained film was 10 μm.

In Comparative Example 1, the residual film ratio of the film after pattern formation was 66%, which was almost the same as in Examples 1 to 4, but the film after imidization was blackish brown and had a base color. I couldn't see through the SUS foil.

Comparative Example 2 The same solution of the polyamic acid resin as in Example 1 was used, and 1-ethyl-3,5-dimethoxycarbonyl-4 was added to 100 parts by weight of the polyamic acid resin (solid content). 10 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine was added and uniformly dissolved by stirring to obtain a solution of a photosensitive resin composition containing no carboxylic acid derivative.

Thereafter, a negative type pattern film of a polyamic acid resin is formed on the SUS foil in the same manner as in Example 1, and imidization is performed at 385 ° C. in the same manner as in Example 1 to form a polyimide resin. A film was formed.

In Comparative Example 2, the film after imidization was not much colored, and the underlying SUS foil was seen through sufficiently, but the residual film ratio of the film after pattern formation was 4
It was 6%, which was lower than those of Examples 1 to 4 and could not be practically used.

Comparative Example 3 The same solution of the polyamic acid resin as in Example 1 was used, and 1-ethyl-3,5-dimethoxycarbonyl-4 was added to this solution based on 100 parts by weight of the polyamic acid resin (solid content). 5 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine was added and uniformly dissolved with stirring to obtain a solution of a photosensitive resin composition containing no carboxylic acid derivative.

Then, a negative type pattern film of a polyamic acid resin is formed on the SUS foil in the same manner as in Example 1, and imidization is performed at 385 ° C. in the same manner as in Example 1 to form a polyimide resin. A film was formed.

In Comparative Example 3, the film after imidization was not much colored, and the underlying SUS foil was seen through sufficiently, but the residual film ratio of the film after pattern formation was 2
It was 8%, which was lower than those of Examples 1 to 4 and could not be practically used.

Comparative Example 4 The same solution of the polyamic acid resin as in Example 1 was used, and 1-ethyl-3,5-dimethoxycarbonyl-4 was added to 100 parts by weight of the polyamic acid resin (solid content). 2 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine was added and uniformly dissolved by stirring to obtain a solution of a photosensitive resin composition containing no carboxylic acid derivative.

Thereafter, a negative type pattern film of a polyamic acid resin is formed on the SUS foil in the same manner as in Example 1, and imidization is performed at 385 ° C. in the same manner as in Example 1 to form a polyimide resin. A film was formed.

In Comparative Example 4, the film after imidization was not so much colored and the underlying SUS foil was seen through sufficiently, but the residual film ratio of the film after pattern formation was 2
It was 2%, which was low as compared with Examples 1 to 4, and could not be practically used.

Comparative Example 5 The same polyamic acid resin solution as in Example 1 was used, and 1-ethyl-3,5-dimethoxycarbonyl-4 was added to this solution based on 100 parts by weight of the polyamic acid resin (solid content). 2 parts by weight of-(2-nitrophenyl) -1,4-dihydropyridine and 10 parts by weight of pyromellitic acid were added,
The solution was uniformly stirred and dissolved to obtain a solution of the photosensitive resin composition containing no carboxylic acid derivative.

Thereafter, a negative type pattern film of polyamic acid resin was formed on the SUS foil in the same manner as in Example 1, and imidization was performed at 385 ° C. in the same manner as in Example 1 to form a polyimide resin. A film was formed.

In Comparative Example 4, the film after imidization was not so much colored and the underlying SUS foil was sufficiently transparent, but 1-ethyl-3,5-dimethoxycarbonyl-4- Since the compounding amount of (2-nitrophenyl) -1,4-dihydropyridine was less than 5 parts by weight, the residual film ratio of the film after pattern formation was 29% even if pyromellitic acid was compounded. It was low as compared with 1 to 4, and it was not practically usable.

The results of the above Examples and Comparative Examples are summarized in Table 1.

[0078]

[Table 1]

EFFECTS OF THE INVENTION According to the photosensitive resin composition of the present invention, a high negative film ratio and a high negative resolution are obtained in a range in which transparency is maintained without using a large amount of a photosensitizer for coloring a film. Can be formed as a film of the pattern.

Since the compounding amount of the photosensitizer is small, it can be formed as a light-colored film with little coloring by imidizing it by heating, and it has heat resistance, electrical properties and mechanical properties. It can be formed as a film of a polyimide resin having excellent properties.

Therefore, such a photosensitive resin composition of the present invention is used for forming an insulating layer such as an interlayer insulating layer or a surface protective layer used for insulating or protecting a solid element or a circuit board in the semiconductor industry. The obtained circuit board can be effectively used as a highly reliable circuit board.

[Brief description of drawings]

FIG. 1 is a process chart of one embodiment showing a method for forming an insulating layer of a circuit board using the photosensitive resin composition of the present invention, (a) is a step of preparing a base material, and (b) is a step of preparing a base material. ) Is a step of forming a film of the photosensitive resin composition on the substrate, (c)
Is a step of exposing the film through a photomask, (d) is a step of developing the film, and (e) is a step of developing the film.
The process of hardening a film and forming an insulating layer is shown.

FIG. 2 is a process diagram of an embodiment showing a method for forming a circuit board following FIG. 1, in which (a) is a process of forming a conductor layer on an insulating layer in a predetermined circuit pattern; b) is
The process of forming a surface protection layer on a conductor layer is shown.

FIG. 3 is a process drawing of another embodiment showing a method for forming a circuit board using the photosensitive resin composition of the present invention,
(A) is a step of preparing a two-layer base material, (b) is a step of forming a conductor layer of the two-layer base material into a predetermined circuit pattern,
(C) shows a step of forming a surface protective layer having an opening on the conductor layer.

[Explanation of symbols]

1 base material 2 Photosensitive resin composition 3 photo mask 4 base layer 6 Surface protection layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/28 H05K 3/28 D (72) Inventor Naotaka Kaneshiro 1-2, Shimohozumi, Ibaraki-shi, Osaka No. Nitto Denko Corporation F-term (reference) 2H025 AA01 AA02 AA10 AA20 AB15 AC01 AD01 BD10 CB25 CC20 FA29 5E314 AA24 AA27 BB01 CC01 FF01 GG17

Claims (5)

[Claims] 1. A polyamic acid resin and 5 to 10 parts by weight of 1,4 with respect to 100 parts by weight of the polyamic acid resin.
-A photosensitive resin composition comprising a dihydropyridine derivative and a carboxylic acid derivative represented by the following general formula (1). [Chemical 1] (In the formula, R represents an organic group, and n represents a number of 1 to 6.) 2. The photosensitive material according to claim 1, which contains 5 to 40 parts by weight of the carboxylic acid derivative represented by the general formula (1) with respect to 100 parts by weight of the polyamic acid resin. Resin composition. 3. The photosensitivity according to claim 1, wherein the carboxylic acid derivative represented by the general formula (1) is at least one of pyromellitic acid, isophthalic acid and succinic acid. Resin composition. 4. A circuit board having an insulating layer obtained from the photosensitive resin composition according to claim 1. 5. A circuit board having a surface protective layer obtained from the photosensitive resin composition according to claim 1.