JP2002069159A - Photosensitive epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive epoxy resin composition which is low dielectric loss tangent capable of developing in the noncombustible aqueous solution. SOLUTION: This photosensitive epoxy resin composition comprises (a) 40-70 pts.wt. multifunctional epoxy resin, (b) 30-60 pts.wt. phenolic hydroxy group- containing resin and 1-10 pts.wt., based on the sum of (a) and (b) of 100 pts.wt., photo acid generation agent and is characterized by using a resin having an alicyclic structure as at least the (b) component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive epoxy resin composition used for a high-density printed wiring board for establishing electrical continuity between layers by blind via holes.

[0002]

2. Description of the Related Art High-density mounting of printed wiring boards for the purpose of reducing the size and weight of electronic devices has been active. In particular, bare chips, CSP (Chip Size Package), BGA (B
For high-density mounting such as all grid arrays, a method of manufacturing a build-up type printed wiring board for providing conduction between layers in a blind via hole having a high degree of freedom in wiring formation is often used.

[0003] Printed wiring boards in the build-up system are:
It is required to be able to withstand heating during component mounting such as a reflow process or a gold wire bonding process.

On the other hand, in forming a blind via hole,
There are high-precision drilling, laser processing, and photo processes using photosensitive resin.
A photo process is adopted.

In the laser processing, there is almost no limitation in selecting a resin material for the insulating layer, but it is necessary to use an apparatus having a high running cost such as an excimer laser for processing a fine blind via hole. On the other hand, in the photo process, it is necessary to use a photosensitive resin as an insulating layer. However, since a large number of blind via holes can be collectively formed by a simple device, it is advantageous in terms of productivity.

In order to manufacture a high-density printed wiring board by a build-up method by such a photo process, a photosensitive resin composition of an alkali development or semi-water development type having excellent heat resistance after curing is required (particularly). Kaihei 11-498
No. 47, JP-A-10-41633, JP-A-9-873
No. 66), an insulating film having high resolution and high heat resistance can be formed using a quasi-water developer containing an organic solvent or an alkali component.

However, the photosensitive epoxy resin composition has not taken sufficient measures to increase the processing speed of a computer, increase the number of channels of a communication device, and increase the frequency of an electric signal for digitization. Plastics, No. 45,
On page 38 (1994), the dielectric loss of an electric signal is caused by the increase in the frequency of the signal.
The electric signal increases as dielectric constant × dielectric loss tangent, and the electric signal is attenuated. Therefore, the photosensitive epoxy resin composition is also strongly required to reduce the dielectric loss.

[0008] Such a resin having a low dielectric loss tangent often reduces the content of polar groups, particularly hydroxyl groups, in the resin,
It is performed by introducing a bulky alicyclic structure. However, with such a resin, development with a nonflammable aqueous solution is difficult, so conventionally, the processing of a blind via hole of a printed wiring board using a low dielectric loss tangent material as an insulating layer has been performed using an organic solvent development type photosensitive material. Photo process using resin,
Laser processing and drill processing were adopted.

As an example, a method is disclosed in which an epoxy resin in which an epoxy group is introduced into a cyclic olefin having no hydroxyl group in the structure is used as an insulating layer (JP-A-8-259784).
The photolithography or laser processing using an organic solvent as a developer is used for processing the blind via hole. However, for processing blind via holes,
From the viewpoint of the via diameter which can be processed, productivity, safety during processing, and the like, a photosensitive resin composition having a low dielectric loss tangent of an alkali or quasi-water developing type is strongly desired.

[0010]

In order to reduce the dielectric loss tangent of an alkali developing type photosensitive resin composition, a thermosetting low dielectric loss tangent epoxy resin having an alicyclic structure in its main chain (about 35% by weight) is used. To a photocurable carboxylic acid-modified epoxy acrylate (about 65% by weight).
-163328). However, since this photosensitive resin composition contains a large amount of epoxy acrylate having a carboxyl group, there has been a problem that the dielectric loss tangent of the cured product shows a high value.

An object of the present invention is to provide a low dielectric loss tangent photosensitive epoxy resin composition which can be developed with a nonflammable aqueous solution.

[0012]

[Means for Solving the Problems] The photosensitive epoxy resin composition of the present invention comprises (a) a polyfunctional epoxy resin 40 to 7;
0 parts by weight, (b) Resin 30 having a phenolic hydroxyl group
(C) a photosensitive epoxy resin composition containing 1 to 10 parts by weight of a photoacid generator with respect to 100 parts by weight of the total of the components (a) and (b); The component (1) is a photosensitive epoxy resin composition having an alicyclic structure.

2. (E) 5 to 50 parts by weight of a carboxylic acid-modified epoxy acrylate optionally having an alicyclic structure, based on 100 parts by weight of the total amount of the components (a) and (b);
The photosensitive epoxy resin composition contains 0.1 to 10 parts by weight of a photo-radical polymerization initiator.

3. As the component (a), (a1) 20 to 50 parts by weight of a bifunctional epoxy resin having an epoxy equivalent of 90 to 190 g / eq, and (a2) an epoxy equivalent of 160 to 3
A mixture of 50 to 20 parts by weight of a trifunctional or higher epoxy resin of 00 g / eq.

[0015] 4. Further, the total amount of the components (a) and (b) is 1
(F) 5 to 30 parts by weight of inorganic filler,
(G) 0.1 to 10 parts by weight of thermal acid generator, (h) sensitizer 0.1.
The photosensitive epoxy resin composition contains 1 to 5 parts by weight.

It has been reported that it is effective to reduce the dielectric loss tangent of a resin by reducing the number of hydroxyl groups in the resin structure and introducing an alicyclic structure (Japanese Patent Application Laid-Open No. Hei 8 (1996)).
No. 259784, JP-A-5-163328, Journal of Japan Institute of Circuit Packaging, Vol. 10, pp. 143-147, 1995
Years). However, regarding the low dielectric loss tangent of a photosensitive resin composition that can be developed with an aqueous alkali solution, or a nonflammable quasi-water developer containing some organic solvent,
Little was considered.

This is because the introduction of a phenolic hydroxyl group or a carboxyl group, which is an alkali-soluble component required for development with an aqueous alkali solution or a quasi-water developer, is contrary to the low dielectric loss tangent.

For example, Japanese Patent Application Laid-Open No. 10-41633 discloses an alicyclic epoxy resin as an example of an epoxy resin contained in a photosensitive epoxy resin composition, but its effect is completely considered. Not.

According to the present invention, a photosensitive epoxy resin composition which is cured by using a photoacid generator and a thermal acid generator in an epoxy resin composition containing an epoxy resin having an alicyclic structure or a phenol novolak resin. Is developed with a quasi-water developer containing an alkali component and a high-boiling organic solvent.
An insulating film having a blind via hole with a dielectric loss tangent at 0.007 to 0.007 to 0.016 could be formed.

This is because the introduction of an alicyclic structure reduces the hydroxyl group concentration, and the secondary hydroxyl group generated by the reaction between the phenolic hydroxyl group, the carboxyl group and the epoxy group is converted by the acid generated from the photoacid generator. It is assumed that the dehydration reaction and the removal from the insulating film further reduced the dielectric loss tangent.

The reaction between a secondary hydroxyl group and an acid is estimated as shown in FIG. 1 (Chem. Mater. Vol. 11, pp. 719).
725 (1999)). In other words, if the introduction of an alicyclic structure and the dehydration reaction using an acid catalyst are used, sufficient low dielectric loss tangent can be obtained even if the resin system contains phenolic hydroxyl groups and carboxyl groups that can be developed with a semi-aqueous developer. Seems to be achievable.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The composition of the photosensitive epoxy resin composition of the present invention will be described. Note that an insulating film having a blind via hole is abbreviated as a photosensitive layer.

The composition of the photosensitive epoxy resin composition suitable for the present invention includes (a) a polyfunctional epoxy resin 40 to 70
Parts by weight, (b) a resin having a phenolic hydroxyl group 30 to 30 parts by weight
60 parts by weight, based on 100 parts by weight of the total amount of the components (a, b), (c) 1 to 10 parts by weight of a photoacid generator,
b) At least one of the components includes a photosensitive epoxy resin composition having an alicyclic structure.

Here, if the amount of the polyfunctional epoxy resin (a) is less than 40 parts by weight, Tg decreases, and if it exceeds 70 parts by weight, development becomes difficult. When the amount of the resin component having a phenolic hydroxyl group as the component (b) is less than 30 parts by weight, the developability is reduced. When the amount exceeds 60 parts by weight, the resistance to Tg and the chemical plating solution is reduced.

With respect to the photoacid generator (c), if it is less than 1 part by weight, curing after exposure becomes insufficient, and the exposed portion may be dissolved during development. If it exceeds 10 parts by weight, the acid counter anion May remain in the photosensitive layer in large amounts, which may adversely affect the insulation properties.

The polyfunctional epoxy resin of the component (a) is
It is a component that forms a latent image by crosslinking with an acid generated from a photoacid generator during exposure and post-heating.

The polyfunctional epoxy resin used as the component (a) has an alicyclic structure in order to reduce the dielectric loss tangent of the photosensitive layer when the component (b) described later does not have an alicyclic structure. It is necessary to select an epoxy resin. There is no particular limitation on the case where the component (b) has an alicyclic structure, but a preferred example is (a1) an epoxy equivalent of 90 to 190 g.
/ Eq bifunctional epoxy resin of 20 to 50 parts by weight, (a
2) Mixtures of trifunctional or higher epoxy resins having an epoxy equivalent of 160 to 300 g / eq.

The component (a1) has a function of lowering the varnish viscosity of the photosensitive epoxy resin composition, filling the inner wiring on the substrate, and planarizing the surface of the photosensitive layer. When it is formed, it has an effect of imparting flexibility to the photosensitive film. Further, by selecting a resin having a small epoxy equivalent, the T of the cured photosensitive layer can be reduced.
g. The resolution can be improved.

If the content of the bifunctional epoxy resin (a1) is less than 20 parts by weight, sufficient improvement in Tg and resolution cannot be expected. If it exceeds 50 parts by weight, the photosensitive layer after drying loses tack-free properties. In some cases, contact exposure of the photomask becomes difficult.

Examples of the component (a1) include various bisphenol A type epoxy resins, bisphenol F type epoxy resins, aliphatic type epoxy resins, and alicyclic epoxy resins. 8
15,828, Daicel Industries Celloxide 2021
P, 2021, 2021A, 3000, Eporide GT
300 and the like. In addition, celloxide is an aliphatic alicyclic epoxy resin.

The component (a2) is a solid trifunctional or higher functional epoxy resin component. In the resin system of the present invention, it is a solid component added mainly for improving tack-free properties. When this resin exceeds 50 parts by weight, the resolution is reduced. If the amount is less than 20 parts by weight, sufficient tack-free properties may not be obtained.

Examples of the epoxy resin include a novolak type, a cresol novolak type epoxy resin, and an epoxy resin obtained by reacting epichlorohydrin with a phenol resin having an alicyclic structure synthesized from dicyclopentadiene and phenol.

Examples of these commercially available products include Yuko Shell Epicoat 180S65 and Sumitomo Chemical's ESCN.
195,220, BREN-104,10 manufactured by Nippon Kayaku
5, EOCN-104, KRM-265 manufactured by Asahi Denka Kogyo
And EXA-7200 manufactured by Dainippon Ink and Chemicals, Inc. E
XA-7200 is an epoxy resin having an alicyclic structure.

The resin having a phenolic hydroxyl group as the component (b) increases the solubility in a semi-aqueous developer to improve the resolution, and at the time of curing, reacts with the epoxy resin to increase the crosslink density and improve the Tg. Component. Preferable examples are not particularly limited when the components (a1) and (a2) have an alicyclic structure. Examples thereof include phenol novolak resins, polyhydroxystyrene, and polyhydroxyphenylmaleimide. As a phenol novolak resin having a ring structure, Nippon Oil DPP synthesized from dicyclopentadiene and phenol
-M.

The photoacid generator (c) is a component that generates an acid upon exposure to light and serves as a curing catalyst for the epoxy resin. Examples include various onium salts, such as BF
₄ , triallylsulfonium salts and diallyl iodonium salts having PF ₆ , AsF ₆ , and SbF ₆ as counter anions; SP-70,172 manufactured by Asahi Denka Kogyo; CI manufactured by Nippon Soda
Commercially available products such as -2855 and 2823 can be used.

In the present invention, the total amount of the components (a) and (b) is 100 parts by weight, and as the component (d), 5 to 50 parts by weight of a carboxylic acid-modified epoxy acrylate which may have an alicyclic structure, It is desirable to contain 0.1 to 10 parts by weight of a photo-radical polymerization initiator as the component (e).

The carboxylic acid-modified epoxy acrylate as the component (d) remarkably improves the solubility of the photosensitive epoxy resin composition in a quasi-aqueous developer and increases the resolution.
This is due to the introduction of a carboxyl group having high solubility in an aqueous alkali solution into the photosensitive layer.

In addition, it has been pointed out that a cured product of an epoxy resin and a phenol novolak resin having an alicyclic structure introduced therein generally has a low crosslink density, and thus has a low Tg. In the photosensitive epoxy resin composition containing (a) to (c) of the present invention, by using a component having a small epoxy equivalent as the component (a), the crosslinking density is increased and the Tg is increased.
Is being improved.

By further adding the carboxylic acid-modified epoxy acrylate of the component (d) to the resin system,
Tg can be remarkably improved. This is considered to be because the carboxyl group of the carboxylic acid-modified epoxy acrylate of the component (d) reacts with the epoxy resin by heating after exposure and development to increase the crosslink density.

The amount of the component (d) is preferably 5 to 50 parts by weight based on the total amount of the components (a) and (b) as 100 parts by weight, and when it is less than 5 parts by weight, the resolution and Tg are sufficiently improved. On the other hand, if it exceeds 50 parts by weight, no further improvement in Tg and resolution is recognized, and conversely, the dielectric loss tangent of the photosensitive layer is significantly reduced.

The component (d) which can be used in the present invention is not particularly limited, and a photosensitive group such as acrylic acid or methacrylic acid is introduced into an epoxy resin such as a phenol novolak type, a cresol novolak type or a bisphenol A type. Epoxy acrylates having a carboxylic acid imparted by reacting a saturated or unsaturated polybasic acid anhydride with a secondary hydroxyl group can be used.

Examples thereof include R-5259 manufactured by Nippon Kayaku,
EXP-14 manufactured by Dainippon Ink having an alicyclic structure in the main chain
21 and others.

The photo-radical polymerization initiator of the component (e) is a photo-polymerization initiator of the carboxylic acid-modified epoxy acrylate of the component (d), and the amount added is 100% of the total of the components (a) and (b). It is desirable that the amount be 0.1 to 10 parts by weight, and sufficient resolution can be obtained in the range of the addition amount. When the addition amount is small, sufficient resolution and improvement in Tg are not observed, and when the addition amount is large, the radical active species generated is too large, polymerization does not proceed sufficiently, and the photosensitive layer may be a hard and brittle cured film. There is.

Examples of the photoradical polymerization initiator (e) include benzoin, benzoin methyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, thioxanthone, and 2,4-diethylthioxanthone. Industrial Irgacure 18
Commercially available products such as 4,261,651,907 can be used.

In the photosensitive epoxy resin composition of the present invention,
The total amount of the components (a) and (b) is 100 parts by weight, and the component (f) is 5 to 30 parts by weight of an inorganic filler, and (g)
It is desirable to add 0.1 to 10 parts by weight of a thermal acid generator as a component and 0.1 to 5 parts by weight of a sensitizer as a component (h).

The inorganic filler of the component (f) improves the tack-free property of the photosensitive layer and lowers the dielectric loss tangent of the photosensitive layer, and also improves the roughening efficiency of the plated surface of the photosensitive layer. . If the amount is less than 5 parts by weight, the above-mentioned effect is not exhibited, and if it exceeds 30 parts by weight, the resolution may be lowered.

Examples of the inorganic filler of the component (f) include silicon oxide, calcium carbonate, aluminum hydroxide and the like. The average particle diameter of the inorganic filler is 0.6 to 1.5 μm, and the range of the variation is 0.6. Those having a thickness of about 05 to 12 μm can be used, but if the inorganic filler is too large, the resolution and insulation reliability are lowered. Commercial products can be used for these inorganic fillers.

The component (g) of the thermal acid generator is a component that newly generates an acid by heating after exposure and development to accelerate curing of the photosensitive layer and increase Tg. Also, the acid generated from the thermal acid generator, together with the acid generated from the photoacid generator,
Epoxy resin and phenol novolak resin during heat curing,
It also has a function of dehydrating secondary hydroxyl groups generated by reaction with carboxylic acid-modified epoxy acrylate.

When the amount is less than 0.1 part by weight, the effect is not sufficiently exhibited. When the amount exceeds 10 parts by weight, a large amount of acid counter anions may remain in the photosensitive layer, which may adversely affect the insulating properties. is there.

Examples of the thermal acid generator as the component (g) include aliphatic onium salts described in JP-A-57-49613 and JP-A-58-37004, for example, 2-butynyltetramethylenesulfonium. Hexafluoroantimonate can be used, and specifically, commercially available products such as Asahi Denka Kogyo's CP-66 and Sanshin Chemical's SI-100L and SI-150L can be used.

The sensitizer (h) is a component for increasing the efficiency of the photocuring reaction, and includes perylene, anthracene, phenothiazine, acridine orange, acridine yellow, benzoflavin, phosphine R, and setoflavin T.
And the like. As a commercially available product, Asahi Denka Kogyo SP-1
00. If the added amount of the sensitizer is less than 0.1 part by weight, a sufficient effect is not recognized, and even if 5 parts by weight or more is added, no further improvement in sensitivity is recognized.

The photosensitive epoxy resin composition of the present invention may further contain a flame retardant, a release agent, a leveling agent, and a rubber component as appropriate in order to improve resin properties and film properties. By using these, characteristics such as flame retardancy, tack-free property, film forming property, and roughening property can be improved.

The flame retardant is a component that contributes to the flame retardation of the photosensitive layer, and a substance known as a flame retardant or a flame retardant auxiliary can be used. Examples thereof include halides of various epoxy resins, red phosphorus, yellow phosphorus, phosphate esters, polyphosphates, polyphosphonates, phosphorus-containing polyols, phosphorus compounds such as polyphosphoric acid, and antimony such as antimony trioxide. -Based flame retardants. The content of the flame retardant is desirably 1 to 10 parts by weight based on 100 parts by weight of all resin components. If the amount is too small, a sufficient flame-retardant effect cannot be obtained, and if the amount is too large, adverse effects such as resolution and plating solution contamination will occur.

The release agent exudes to the surface of the photosensitive layer when the photosensitive layer is dried and cured, and covers the photosensitive layer. Thereby, the tack-free property of the photosensitive layer is improved, and the contact exposure of the photomask is facilitated. Examples of the release agent suitable for the present invention include polysiloxane, polyether, and a copolymer thereof. Commercially available products include Sannopco's Perenol F40, S43 and Toray Dow Corning SC5.
570 and TSA-750 manufactured by Toshiba Silicone. The content of the release agent is from 1 to 5 based on 100 parts by weight of all resin components.
It is desirable to use in the range of parts by weight.

The leveling agent has a function of flattening the photosensitive layer when forming the photosensitive layer. Acrylic ester copolymers are preferably used, and commercially available products include Modaflow manufactured by Monsanto. The content of the leveling agent is desirably 0.1 to 10 parts by weight based on 100 parts by weight of all resin components.

The rubber component functions as a roughening component when the surface of the photosensitive layer is roughened with a mixed solution of chromic acid and an aqueous solution of permanganic acid, and preferably contains rubber fine particles. By dispersing the rubber particles in the photosensitive layer, a decrease in Tg of the photosensitive layer can be suppressed. The rubber particles preferably have an average particle diameter of 0.05 to 0.3 μm, and a maximum of about 1 μm. Such examples include XER-81, 91 manufactured by JSR and YR-51 manufactured by Toto Kasei, in which rubber particles are dispersed in epoxy resin.
6,528. The content of the rubber component is desirably 5 to 20 parts by weight based on 100 parts by weight of all resin components.

The photosensitive epoxy resin composition of the present invention may appropriately contain a solvent. That is, it can be stored and used as a varnish in which each of the above components is dissolved and dispersed in a solvent.

Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and tetrahydrofuran, ethers, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and the like. Glycol derivatives such as glycol ethers, methyl cellosolve acetate, and ethyl cellosolve acetate can be used.

The semi-aqueous developer used for developing the photosensitive epoxy resin composition of the present invention includes a water-soluble boiling point of 100.
A mixed aqueous solution of an organic solvent having a temperature of 100 ° C. or higher and 100 to 500 ml / l, an alkali component of 1 to 20 g / l selected from sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, sodium carbonate and the like is preferable.

By adding a water-soluble organic solvent having a boiling point higher than that of water to the developer, it is possible to prepare a quasi-water developer which is nonflammable and exhibits a higher developability than an alkaline developer.

As the water-soluble high-boiling organic solvent used in the present invention, alcohols such as 2-butoxyethanol, 2,2'-butoxymethoxyethanol and 2,2'-butoxyethoxyethanol can be preferably used.

[0062]

The present invention will be specifically described below with reference to examples and comparative examples. In the following description, “parts” means “parts by weight” unless otherwise specified.

Tables 1 and 2 show the compositions and properties of the photosensitive epoxy resin compositions of the present invention in Examples 1 to 13 and Comparative Examples 1 and 2. Each photosensitive resin composition was used as a methyl ethyl ketone solution having a solid content of 50%.

Further, each material used in the present example and comparative example,
The test method is shown below.

PSF-2803: Cresol novolak type phenol resin manufactured by Gunei Chemical Co., Ltd. b-component DPP-M: Nippon Oil Co., Ltd., phenol novolak resin having an alicyclic structure b component KRM-2650: Asahi Denka Kogyo, cresol novolak type Epoxy resin (220 g / eq) a2 component 2021A: Daicel Industries, aliphatic alicyclic epoxy resin (131 g / eq) a1 component Ep-828: Yuka Shell, bisphenol A type epoxy resin (190 g / eq) … A1 component Silicon oxide: average particle diameter 1 μm… f component SP-70: Asahi Denka Kogyo photoacid generator… c component SI150L: Sanshin Chemical Industries, thermal acid generator… g component SP-100: Asahi Denka Sensitizer: h component R5259: Nippon Kayaku, carboxylic acid-modified epoxy acrylate (68.5 mg KOH / g) ... d components EXP-1421: manufactured by Dainippon Ink, carboxylic acid-modified epoxy acrylate having an alicyclic structure (72 mg KOH
/ G) d component I-184: Nagase Kogyo Co., Ltd., photo-radical initiator e component S43: Polysiloxane copolymer (release agent) manufactured by San Nopco Co., Ltd. Other additives Modaflow: manufactured by Monsanto Co., acrylic ester Polymer: Other additives TPP: triphenylphosphine, thermosetting catalyst: Used in Comparative Example 2.

(1) Measurement of dielectric constant and dielectric loss tangent The photosensitive epoxy resin composition was applied to a copper foil having a thickness of 18 μm with a bar coater, and dried at room temperature for 1 hour and at 90 ° C. for 30 minutes. A photosensitive layer having a thickness of 35 to 50 μm was formed. The sample was exposed to an ultra-high pressure mercury lamp at 1500 mJ / cm ² , and exposed to 90 ° C./30 minutes, 160 ° C./60 minutes, 180 ° C.
C./120 minutes of heating was applied.

After the sample was cooled to room temperature, the copper foil was removed by etching using an aqueous solution of sulfuric acid / hydrogen peroxide solution, washed with water, dried at 110 ° C. for 120 minutes, and cured with a photosensitive epoxy resin composition. Was prepared. An electrode having a diameter of 20 mm was drawn on the surface of the cured film with a silver paste, and a counter electrode was formed with a silver paste on the entire back surface of the cured film.

The cured film after the formation of the electrode is heated at 110 ° C./4
After drying for a time, a sample for measuring dielectric constant and dielectric loss tangent was prepared. The dielectric constant and the dielectric loss tangent are manufactured by Agilent Technologies, 4129A impedance analyzer, 1645
Measurement frequency 1MH using 1B test fixture
The value at z was measured.

In Comparative Example 2 having no photosensitivity, a cured film was prepared in the same manner, and the dielectric constant and the dielectric loss tangent were measured.

(2) Measurement of Glass Transition Temperature (Tg) The cured film was cut into a size of 30 mm × 5 mm to prepare a sample. Made by IT measurement control, DVA-
Tg was determined by measuring dynamic viscoelasticity using a 200. The measurement conditions were a distance between supports of 20 mm, a measurement frequency of 10 Hz, a heating rate of 5 ° C./min, and a measurement range of room temperature to 250 ° C.

(3) Evaluation of Resolution A photosensitive epoxy resin composition was applied to the copper surface of the copper-clad laminate with a bar coater, and dried at 90 ° C. for 30 minutes to obtain a film thickness of 35.
A photosensitive layer having a thickness of ５０50 μm was formed. 10-160 μm in diameter
Was exposed to ultraviolet light from an ultra-high pressure mercury lamp at 1000 to 2500 mJ / cm ² through the via hole mask.

Then, the mixture was heated at 90 ° C. for 30 minutes, cooled to room temperature, and then diluted with a semi-aqueous developer (500 ml / l of 2,2-butoxyethoxyethanol, 10 g / l of sodium hydroxide).
Spray developed for ~ 5 minutes. The diameter of the developable blind via hole was taken as the resolution.

[0073]

[Table 1]

[0074]

[Table 2]

[Examples 1 to 3] Novolak epoxy resin (KRM-2650) as component (a) and phenol novolak resin (D) having an alicyclic structure as component (b)
It is a photosensitive epoxy resin composition containing PP-M). The dielectric loss tangent is 0.0 due to the introduction of the alicyclic structure.
It showed a low value of 12 to 0.014.

The exposure required for development is 2500 mJ.
/ Cm ² , the swelling of the photosensitive layer occurs below this value.
The resolution of Example 1 was 200 μm with a development time of 1 minute, and the resolution of Examples 2 and 3 was 120 μm with a development time of 5 minutes.
m and 140 μm. In the case of Example 1, swelling was observed in the photosensitive layer after long-term development.

Examples 4 to 6 Bisphenol A type epoxy resin (Ep-828), (a1)
2) Novolak type epoxy resin (KRM-2) as a component
650) and (b) a photosensitive epoxy resin containing a novolak epoxy resin (DPP-M) having an alicyclic structure as a component. Due to the introduction of the alicyclic structure, the dielectric loss tangent showed a low value of 0.015 to 0.016.

The exposure required for development is 2500 mJ.
/ Cm ² , the swelling of the photosensitive layer occurs below this value. The resolution at a development time of 5 minutes is 60 to 80 μm,
By adding the component (a-1) having a small epoxy equivalent, the resolution was improved, and the Tg was also improved to 180 to 185 ° C.

Example 7 Bisphenol A type epoxy resin (Ep-828) as component (a1), (a2)
Novolak epoxy resin (KRM-265) as a component
0), a photosensitive epoxy resin composition containing a phenol novolak resin (DPP-M) having an alicyclic structure as a component, and the content of DPP-M having an alicyclic structure was increased to 45 parts. The composition.

The exposure required for development is 2500 mJ.
/ Cm ² , the swelling of the photosensitive layer occurs below this value. The resolution at a development time of 5 minutes was 60 μm, and the resolution was improved as compared with those of Examples 5 and 6 by increasing the phenol novolak resin (DPP-M).

Example 8 In Example 7, silicon oxide was used as the component (f), and a thermal acid generator (SI15) was used as the component (g).
0L) and a photosensitive epoxy resin composition to which a sensitizer (SP100) is added as a component (h).

The addition of silicon oxide and the addition of a thermal acid generator further reduced the dielectric loss tangent, and the value was 0.01.
It was 0. The exposure required for development was reduced to 1000 mJ / cm ² by the addition of the sensitizer. The resolution at a development time of 5 minutes was 60 μm. Further, the addition of the thermal acid generator accelerated the curing of the photosensitive layer, and the Tg became 200 ° C.

[Example 9] (a)
1) A composition using an alicyclic epoxy resin (2021A) instead of Ep828 as a component. The use of 2021A further reduced the dielectric loss tangent, and the value was 0.007.

The exposure required for development is 10
00 mJ / cm ² , and a resolution of 6 minutes in a development time of 5 minutes.
It was 0 μm. Tg was 208 ° C. by using an alicyclic epoxy resin (2021A) having a small epoxy equivalent.
It became.

[Embodiments 10 to 12] (d) in Embodiment 9
Carboxylic acid-modified epoxy acrylate (R5
259) and a photosensitive epoxy resin composition to which a photoradical polymerization initiator is added as a component (e). R525 above
Addition of 9 improved Tg and resolution.

Exposure amount: 1000 mJ / cm ² , development time: 2
The resolution in minutes shows an excellent value of 20 to 40 μm,
Also showed a high value of 209 to 222 ° C. Although the dielectric loss tangent increases with an increase in the amount of R5259 added, the dielectric loss tangent increases by 0.1.
The value was as low as 009 to 0.013.

Example 13 Instead of the carboxylic acid-modified epoxy acrylate (R5259) of Example 12,
(D) A photosensitive epoxy resin composition to which a carboxylic acid-modified epoxy acrylate having an alicyclic structure (EXP1421) is added as a component.

The dielectric loss tangent is as low as 0.012, and Tg is 20
The value was as high as 7 ° C. Exposure amount 1000 mJ / cm ² ,
The resolution at a development time of 2 minutes showed an excellent value of 30 μm.

Comparative Example 1 A conventional photosensitive epoxy resin composition containing no alicyclic structure. The exposure required for development was 2500 mJ / cm ² , and the resolution at a development time of 2 minutes was 25 μm.

Although the resolution (25 μm) and Tg (215 ° C.) show excellent values, the dielectric loss tangent is 0.023.
The values were higher than those of the above examples.

Comparative Example 2 Example 9 having an alicyclic structure
The same resin composition as in Example 1 was cured with TPP as a thermosetting catalyst. The dielectric loss tangent is 0.01 because of having an alicyclic structure.
Although the value was as low as 2, it was confirmed that the value did not reach 0.007 of Example 9 cured with an acid catalyst.

[0092]

According to the present invention, an epoxy resin composition containing at least one epoxy resin having an alicyclic structure or a resin having a phenolic hydroxyl group is prepared by using a photoacid generator and a thermal acid generator. By curing with a light and heat curing system, development with a nonflammable quasi-water developer is possible, and the dielectric loss tangent at 1 MHz after curing is 0.007 to 0.007.
0.016 can be obtained.

By using the photosensitive epoxy resin composition, a printed wiring board having fine blind via holes in an insulating layer having a low dielectric loss tangent can be obtained by a safe and simple photo process using a nonflammable quasi-water developer. Manufacturing becomes possible.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a drawing showing a dehydration reaction of a putative hydroxyl group and an acid.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Mineo Kawamoto 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Haruo Akahoshi 7-1, Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Hiroyuki Fukai 1500 Oji Ogawa, Shimodate City, Ibaraki Prefecture Inside Shimodate Plant, Hitachi Chemical Co., Ltd. F term in Shimodate factory of Kasei Kogyo Co., Ltd. (reference)

Claims (4)

[Claims] 1. (a): polyfunctional epoxy resin 40 to 70
Parts by weight, (b): resin 30 having a phenolic hydroxyl group
(C): In a photosensitive epoxy resin composition containing 1 to 10 parts by weight of a photoacid generator, based on 100 parts by weight of the total of the components (a) and (b), at least the component (b) Is a resin having an alicyclic structure. 2. The total amount of the components (a) and (b) is 100 parts by weight, and the component (d): 5 to 50 parts by weight of a carboxylic acid-modified epoxy acrylate which may have an alicyclic structure; 2. The photosensitive epoxy resin composition according to claim 1, which contains 0.1 to 10 parts by weight of a photoradical polymerization initiator. 3. The composition according to claim 1, wherein the component (a) is (a1): a bifunctional epoxy resin having an epoxy equivalent of 90 to 190 g / eq.
50 parts by weight and (a2): epoxy equivalent of 160 to 300
The photosensitive epoxy resin composition according to claim 1, wherein the photosensitive epoxy resin composition is a mixture of 50 to 20 parts by weight of a trifunctional or higher epoxy resin of g / eq. 4. The total amount of the components (a) and (b) is 100 parts by weight, and (f): 5 to 30 parts by weight of an inorganic filler;
The photosensitive epoxy resin composition according to claim 1, 2 or 3, comprising (g): 0.1 to 10 parts by weight of a thermal acid generator, and (h): 0.1 to 5 parts by weight of a sensitizer.