JPH08151507A - Epoxy resin composition for laminate - Google Patents

Abstract

PURPOSE: To obtain the subject composition capable of producing a laminate having excellent solder resistance after moisture absorption, comprising a specific phenolic compound in a prescribed ratio. CONSTITUTION: This composition comprises (A) an epoxy resin containing >=60wt.% a bisphenol A type epoxy resin having <=1,000 epoxy equivalent based on the whole amount of the epoxy resin, (B) a curing agent composed of (i) a novolak resin of phenol and/or cresol and (ii) a phenolic compound having a skeleton of formula I to formula IV (R1 and R2 are each H or a <=9C alkyl) in the ratio of the component (ii) based on the whole amount of the component B of >=20wt.%, preferably 20-80wt.% and (C) 1.5-10 pts.wt. of a phenoxy resin having 5,000-100,000 weight-average molecular weight based on 100 pts.wt. of the total of components A and B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for laminates used for producing laminates used in electric / electronic equipment.

[0002]

2. Description of the Related Art Conventionally, a laminated board used for electric / electronic devices is obtained by impregnating a base material such as a glass cloth with a varnish made of an epoxy resin composition and then drying it to laminate a plurality of prepregs. It is manufactured by arranging copper foil on the top and bottom of the copper foil and then molding. In the epoxy resin composition used for this purpose, an amine-based curing agent such as dicyandiamide is generally used as a curing agent. In recent years, with an increase in mounting density, a laminated plate having more excellent heat resistance than before has been demanded, and a phenol-based curing agent having more excellent heat resistance than a conventional amine-based curing agent has been studied. (For example, Japanese Patent Application Laid-Open No. 3-79621) When manufacturing a laminated plate, if the dry state of the prepreg is insufficiently heated, the resin will flow out during molding, resulting in a defective plate thickness. If so, a minute void is generated in the obtained laminated plate, that is, a so-called defective scratch occurs,
In the case of conventional amine-based curing agents, in order to prevent such defects, the drying conditions that can produce a prepreg having both the time until gelation (hereinafter abbreviated as gelation time) and melt viscosity suitable for lamination molding It was possible to set.

However, in an epoxy resin composition using a phenol-based curing agent, it is considered that three-dimensional crosslinking proceeds in the course of the curing reaction without the molecules of the epoxy resin or the like extending linearly. Since the phenomenon of gelation occurs immediately after the start of the increase in melt viscosity, it is difficult to manufacture prepregs that have both the gelling time and melt viscosity suitable for laminate molding, no matter how the prepreg manufacturing conditions are adjusted. It was

Therefore, the present inventors have obtained a prepreg having an appropriate gelling time and melt viscosity, and having excellent moldability, by incorporating a phenoxy resin which functions to increase the melt viscosity into the epoxy resin composition. It has been found that this is possible, and Japanese Patent Application No. 6-115723 proposes this configuration.

However, when the curing agent is a novolac resin of phenol and / or cresol, the solder heat resistance after moisture absorption is insufficient, especially between the inner layer circuit surface and the prepreg of the multilayer board having the inner layer circuit. A solder heat resistance test after moisture absorption revealed that there is a problem that peeling is likely to occur.

[0006]

In view of the above circumstances, the present invention uses an epoxy resin composition for laminates containing an epoxy resin, a curing agent composed of a novolac resin of phenol and / or cresol, and a phenoxy resin. It is an object to improve the solder heat resistance after moisture absorption of the obtained laminated board.

[0007]

The epoxy resin composition for laminated plates according to the present invention has an epoxy resin, a curing agent, and 1.5 parts by weight per 100 parts by weight of the total amount of the epoxy resin and the curing agent.
-10 to 10 parts by weight, weight average molecular weight of 5000 to 1000
In the epoxy resin composition for a laminated board containing a phenoxy resin of 00, the epoxy equivalent of the epoxy resin is 1
Bisphenol A type epoxy resin of 000 or less is contained in an amount of 60% by weight or more of the entire epoxy resin, and a phenol and / or cresol novolak resin as a curing agent, and any one selected from the group represented by the following formulas It is characterized in that it contains a phenolic compound having a skeleton, and the content ratio of the phenolic compound is 20% by weight or more based on the whole curing agent. In the formulas below, R, R ₁ and R ₂ represent a hydrogen atom or an alkyl group having up to 9 carbon atoms.

[0008]

[Chemical 7]

[0009]

Embedded image

[0010]

[Chemical 9]

[0011]

[Chemical 10]

[0012]

[Chemical 11]

[0013]

[Chemical 12]

The epoxy resin composition for a laminated board according to a second aspect of the present invention is the epoxy resin composition for a laminated sheet according to the first aspect, wherein the content ratio of the novolac resin of phenol and / or cresol is the entire curing agent. Content of the phenolic compound having any one skeleton selected from the group represented by the above formulas is 20 to 80% by weight based on the whole curing agent. Is characterized by.

The present invention will be described in detail below. The epoxy resin used in the present invention contains a bisphenol A type epoxy resin having an epoxy equivalent of 1000 or less in an amount of 60% by weight or more based on the whole epoxy resin. Epoxy equivalent is 10
A bisphenol A type epoxy resin (including a halogenated type) having a molecular weight of 00 or less has an appropriate melt viscosity, and has a higher molecular weight in the course of curing reaction than a polyfunctional epoxy resin having three or more functional groups. Since it can be linearly extended, it is characterized in that rapid three-dimensional cross-linking does not proceed, and it is easy to control the gelling time of the prepreg. Therefore, the main component of the epoxy resin composition for laminated boards of the present invention To use as. The bisphenol A type epoxy resin having an epoxy equivalent of 1,000 or less and the phenoxy resin described below both have a basic skeleton called a bisphenol skeleton, but are greatly different in the molecular weight.

The phenoxy resin used in the present invention is not particularly limited, but a linear polymer synthesized from bisphenol A or tetrabromobisphenol A and epichlorohydrin can be exemplified.
In the present invention, a phenoxy resin having a weight average molecular weight of 5,000 to 100,000 is used. Weight average molecular weight is 50
When it is less than 00, it becomes difficult to obtain a prepreg having an appropriate gelling time and melt viscosity and having improved moldability, and when it is more than 100000, the solubility in a solvent is poor, This is because it becomes difficult to form a resin composition having a uniform solution. Regarding the compounding amount of the phenoxy resin, the total amount of the epoxy resin and the curing agent is 10
Phenoxy resin is mixed in an amount of 1.5 to 10 parts by weight with respect to 0 parts by weight. When it is less than 1.5 parts by weight, it becomes difficult to obtain a prepreg having an appropriate gelling time and melt viscosity and improved in moldability, and when it exceeds 10 parts by weight, the mechanical properties of the resulting laminate are improved. This is because there arises a problem that the strength (bending strength etc.) is lowered.

The present invention is characterized by containing a novolac resin of phenol and / or cresol as a curing agent and a phenolic compound having any one skeleton selected from the group represented by the above formulas (1) to (3). I am trying.
The phenol and cresol novolak resins used in the present invention can be obtained by a method of synthesizing phenol or cresol and formaldehyde by dehydration condensation, and thus are excellent in terms of availability of raw materials, and with an epoxy resin. It has the property of high reactivity.

Further, a phenolic compound having a skeleton selected from the group represented by the above formulas (1) to (3) is used in combination with a novolac resin of phenol and / or cresol, and the content ratio of the phenolic compound is Is 20% by weight or more based on the total amount of the curing agent, it is possible to improve the solder heat resistance after moisture absorption of the obtained laminate. In addition,
Regarding the ratio, when the total amount of the curing agent is 100% by weight, the content ratio of the novolac resin of phenol and / or cresol is 20 to 80% by weight of the entire curing agent,
The content of the phenolic compound having any one skeleton selected from the groups represented by the formulas (1) to (20) is preferably 20 to 80% by weight based on the whole curing agent. This is because if the proportion of the novolac resin of phenol and / or cresol is less than 20% by weight, the problem of deterioration in curing reactivity tends to occur. Regarding the amount of the curing agent blended in the epoxy resin composition, it is desirable to blend 0.6 to 1.3 phenolic hydroxyl group equivalents of the curing agent with respect to one epoxy group equivalent of the epoxy resin. If it is out of this range, the problem that the heat resistance of the obtained laminate is impaired is likely to occur.

In the present invention, the epoxy resin composition may contain a curing accelerator, a solvent and the like, if necessary. The curing accelerator that can be used is not particularly limited, but tertiary amines such as 1,8-diaza-bicyclo (5,4,0) undecene-7, triethylenediamine and benzyldimethylamine, 2-methyl Imidazole, 2-ethyl 4-
Imidazoles such as methylimidazole and 2-phenylimidazole, organic phosphines such as tributylphosphine and triphenylphosphine (phosphorus curing accelerator), tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate Etc. can be illustrated. The solvent that can be used is not particularly limited, but examples thereof include ketones such as acetone and methyl ethyl ketone, ethers such as ethylene glycol monomethyl ether, and aromatic hydrocarbons such as benzene and toluene.

[0020]

In the present invention, a phenol compound having a skeleton selected from the groups represented by the formulas (1) to (4) is used as a curing agent in combination with a novolac resin of phenol and / or cresol, and When the content ratio of the system compound is 20% by weight or more based on the total amount of the curing agent, it has an effect of improving the solder heat resistance after moisture absorption of the obtained laminate.

[0021]

EXAMPLES The present invention will be described below based on Examples and Comparative Examples.

Examples 1 to 7 and Comparative Examples 1 to 3 As epoxy resins, the following two kinds of epoxy resins were blended in the ratios shown in Tables 1 and 2 and used. Epoxy resin 1 --- Epoxy equivalent of 500, tetrabromobisphenol A type epoxy resin [Dow Chemical Company, trade name DER511] Epoxy resin 2--epoxy equivalent of 220, cresol novolac type epoxy resin [Toto Kasei Co., Ltd.
Made, product name YDCN704]

As the curing agent, the following seven kinds of phenolic curing agents were mixed and used in the ratios shown in Tables 1 and 2. (1) Curing agent 1 ---- Bisphenol A novolac resin having a skeleton of the above formula [Dainippon Ink and Chemicals, Inc.
Made by trade name VH4170, softening point 105 ° C., hydroxyl equivalent 118] (2) Hardener 2 --- Dicyclopentadiene / phenol copolymer having the skeleton of the above formula (R in the formula is a hydrogen atom) [Nippon Oil Co., Ltd.] Co., Ltd., trade name DPP600M, softening point 93 ° C., hydroxyl group equivalent 170] (3) Curing agent 3 --- p-xylene-phenol copolymer having the skeleton of the above formula (R in the formula is a hydrogen atom) [ Mitsui Toatsu Chemicals, Inc., trade name XL-225L, softening point 85
° C, hydroxyl equivalent 180] (4) Curing agent 4 --- Divinylbenzene / phenol copolymer having the skeleton of the above formula (R in the formula is a hydrogen atom) [trade name, manufactured by Dainippon Ink and Chemicals, Inc.] CZ-256
A, softening point 85 ° C., hydroxyl equivalent 200] (5) Curing agent 5 --- Special phenolic resin having the skeleton of the above formula (R in the formula is a hydrogen atom) [Nippon Oil Co., Ltd.]
Made, trade name PP-700-300, softening point 148 ° C, hydroxyl equivalent 317] (6) Curing agent 6 --- Special phenolic resin having the skeleton of the above formula (R ₁ and R ₂ in the formula are hydrogen atoms) [Yukaka Shell Epoxy Co., Ltd., trade name YL-6065, softening point 122 ° C., hydroxyl equivalent 100] (7) Hardener 7 --- phenol novolac resin [Arakawa Chemical Industry Co., Ltd., trade name Tamanol 752, softening point 80 ° C, hydroxyl equivalent 105]

As the phenoxy resin, a phenoxy resin having a weight average molecular weight of 42600 and a number average molecular weight of 11,200 is manufactured by Union Carbide Co., trade name PKH.
H] was blended and used in the proportions shown in Tables 1 and 2.

Triphenylphosphine was used as the curing accelerator, and methyl ethyl ketone (abbreviated as MEK) was used as the solvent in the proportions shown in Tables 1 and 2, respectively.

The above raw materials were blended in the formulations shown in Table 1 and Table 2, mixed and dissolved to obtain a varnish-like epoxy resin composition. The obtained epoxy resin composition has a thickness of 0.1 m.
m plain weave glass cloth was impregnated and then dried at 150 ° C. to make a prepreg having a resin content of about 50% by weight. Next, a 0.5 mm thick double-sided copper clad laminate (FR
-4 type) copper foil (thickness: 35 μm) whose surface is blackened is used as a core material, one prepreg obtained above is placed on each side of the core material, and a copper foil having a thickness of 18 μm is provided on both outer sides thereof. Then, the laminate is sandwiched between metal plates, and the laminate is sandwiched between metal plates and pressed and heated under the conditions of a pressure of 40 kg / cm ² , a temperature of 170 ° C. and a time of 60 minutes to form a multilayer laminate. .

The outer layer copper foil (thickness 18 μm) of the multi-layer laminated plate produced above was removed by etching to give a thickness of 50 mm.
It cut | disconnected to the size of * 50mm, and produced the sample for evaluation. This evaluation sample is called Pressure Cooker Test (PCT) and is subjected to moisture absorption treatment in saturated steam at 121 ° C for 3 hours, and immediately after the treatment, it is immersed in solder at 260 ° C for 10 seconds to test for the occurrence of blistering. did. The solder heat resistance test after moisture absorption was performed on 10 evaluation samples for each of the Examples and Comparative Examples, and the results are shown in Tables 1 and 2.

[0028]

[Table 1]

[0029]

[Table 2]

From the results shown in Tables 1 and 2, it was confirmed that each example had better solder heat resistance after moisture absorption than each comparative example.

[0031]

The epoxy resin composition for laminated boards of the present invention has a novolac resin of phenol and / or cresol as a curing agent and any one skeleton selected from the groups represented by the above formulas (1) to (3). According to the present invention, a curing agent comprising a novolac resin of phenol and / or cresol is used, since it contains a phenolic compound and the content ratio of the phenolic compound is 20% by weight or more of the entire curing agent. It is possible to supply a resin composition containing a phenoxy resin, which is an epoxy resin composition for a laminated plate, and which gives a laminated plate having excellent solder heat resistance after moisture absorption.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display location // H05K 3/46 T 6921-4E (72) Inventor Eiji Eiji Kadoma, Osaka Prefecture No. 1048 Matsushita Electric Works Co., Ltd. (72) Inventor Yukihiro Hatta, Kadoma City, Osaka Prefecture 1048 Kadoma, Matsushita Electric Works Co., Ltd.

Claims (2)

[Claims] 1. An epoxy resin, a curing agent, and 1.5 to 10 relative to 100 parts by weight of the total amount of the epoxy resin and the curing agent.
In the epoxy resin composition for laminates, which contains phenoxy resin having a weight average molecular weight of 5,000 to 100,000 as a weight part, an epoxy equivalent of 1000 as an epoxy resin
The following bisphenol A type epoxy resin is contained in an amount of 60% by weight or more based on the whole epoxy resin, a novolac resin of phenol and / or cresol as a curing agent, and any one skeleton selected from the group represented by the following formulas An epoxy resin composition for a laminated board, comprising a phenolic compound having: and a content of the phenolic compound being 20% by weight or more based on the total amount of the curing agent.
(In the formula, R, R ₁ and R ₂ represent a hydrogen atom or an alkyl group having up to 9 carbon atoms.) Embedded image Embedded image [Chemical 4] Embedded image [Chemical 6] 2. A phenol and / or cresol novolac resin content of 20 to 80% by weight of the total curing agent.
And the content of the phenolic compound having any one skeleton selected from the group represented by the formulas is 20 to 80% by weight based on the total amount of the curing agent. 1. The epoxy resin composition for laminated boards according to 1.