JPH08120246A - Adhesive for metal-foil-clad laminate - Google Patents

Abstract

PURPOSE: To provide an adhesive for a metal-foil-clad laminate having high tracking resistance, good soldering-heat resistance and excellent storage stability. CONSTITUTION: This adhesive comprises 100 pts.wt. polyvinyl butyral resin, 10-40 pts.wt. epoxy resin, 40-80 pts.wt. melamine resin, 2-20 pts.wt. phenolic resin and 3-30 pts.wt. blocked isocyanate. Alternatively, it comprises 0.005-5 pts.wt. organic acid per 100 pts.wt., in total, the polyvinyl butyral resin, the epoxy resin, the melamine resin, the phenolic resin and the blocked isocyanate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal foil-clad laminate adhesive for use in bonding a metal foil of a metal foil-clad laminate, for example, a copper foil, to the laminate.

[0002]

The performance of metal foil clad laminates such as phenolic resin copper clad laminates is greatly affected by the type of adhesive used to bond the metal foil such as copper foil to the laminate. Conventionally, as an adhesive having good heat resistance and peeling strength, an adhesive containing polyvinyl butyral resin, epoxy resin, and phenol resin as main components has been widely used.

In recent years, along with the demand for higher density of printed wiring boards used in electronic equipment, general-purpose type phenol resin copper clad laminates are no exception, and have a tracking resistance of about 250V and higher than 500V. Tracking resistance is required. Therefore, in order to secure high tracking resistance, an adhesive containing a melamine resin in addition to a polyvinyl butyral resin, an epoxy resin, and a phenol resin is used. However, this adhesive has a drawback in that, for example, when the storage period is long, the solder heat resistance is lowered and the storage stability is poor.

[0004]

The present invention has been made in view of the above circumstances, and an object thereof is to have high tracking resistance, good solder heat resistance, and storage stability. An object of the present invention is to provide an adhesive for metal foil-clad laminates that has excellent properties.

[0005]

The adhesive for metal foil-clad laminates according to claim 1 of the present invention is an adhesive used for adhering a metal foil to a laminate, and is 100 parts by weight of polyvinyl butyral resin. On the other hand, the epoxy resin is 10 to 40 parts by weight, the melamine resin is 40 to 80 parts by weight, the phenol resin is 2 to 20 parts by weight, and the blocked isocyanate is 3 to 30 parts by weight.
The content of the organic acid is 0.005 to 5 parts by weight based on 100 parts by weight of the polyvinyl butyral resin, the epoxy resin, the melamine resin, the phenol resin, and the blocked isocyanate. It is characterized by containing in.

The adhesive for metal foil-clad laminates according to claim 2 of the present invention is the adhesive for metal foil-clad laminates according to claim 1, in which the blocking agent for the blocked isocyanate is phenol, alkylphenol or oxime. It is characterized by comprising at least one.

The adhesive for metal foil-clad laminate according to claim 3 of the present invention is the adhesive for metal foil-clad laminate according to claim 1 or 2, wherein the organic acid is an aromatic carboxylic acid,
And at least one of aliphatic carboxylic acids.

The present invention will be described in detail below. The adhesive for metal foil-clad laminates of the present invention is, for example, an adhesive applied to a copper foil to adhere the copper foil to the laminate. The adhesive for metal foil-clad laminates of the present invention is polyvinyl butyral resin, epoxy resin, melamine resin, blocked isocyanate, and
Contains an organic acid.

The polyvinyl butyral resin is not limited, but as a commercially available product, specifically, S-REC B is used.
X-1, BX-2, BX-5, KS-5 (trade name of Sekisui Chemical Co., Ltd.), and Denka Butyral 400
0, 5000-A, 6000-C, 6000-EP, 6
000-AP, BY-245 (trade name of Denki Kagaku Kogyo Co., Ltd.) and the like. These resins are single and
It is used as a mixture of two or more species.

The metal foil-clad laminate adhesive of the present invention contains an epoxy resin in an amount of 10 to 40 parts by weight based on 100 parts by weight of the polyvinyl butyral resin. If the amount of the epoxy resin is less than 10 parts by weight, the solder heat resistance is lowered, and if it exceeds 40 parts by weight, the tracking resistance is deteriorated. The epoxy resin is, for example, an epoxy resin (phenolic epoxy resin) or an alicyclic epoxy which is a glycidyl ether of phenols such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, resol type epoxy resin, and bisphenol type epoxy resin. Resin, epoxidized butadiene, halogenated epoxy resin,
A flexible epoxy resin, a polyfunctional epoxy resin, etc. are mentioned. Among them, phenol type epoxy resin, or
A mixture of a phenol type epoxy resin and a polyfunctional epoxy resin, or epoxidized butadiene is preferable because of its excellent heat resistance and peel strength. Specific examples of commercially available products include Epotote YDCN701 and Epotote YDCN.
609 (trade name manufactured by Tohto Kasei Co., Ltd.), Epicort-1
52, 154, 180S65, 815, 828, 100
1, 1002, 1004, 1007 (trade name of Yuka Shell Epoxy Co., Ltd.), TEPIC (trade name of Nissan Chemical Co., Ltd.), BF1000 (trade name of ADEKA ARGUS CORPORATION), R-45 EPI (Izumi Petrochemical Co., Ltd.) Product name) and the like. These epoxy resins may be used alone or in combination of two or more.

The metal foil-clad laminate adhesive of the present invention contains a melamine resin in an amount of 40 to 80 parts by weight based on 100 parts by weight of the polyvinyl butyral resin. If the amount of the melamine resin is less than 40 parts by weight, the tracking resistance is lowered, and if it exceeds 80 parts by weight, the solder heat resistance is deteriorated. Examples of the melamine resin include unmodified melamine resin, and alkyl etherified melamine resin that has been alkyl etherified, and among them, alkyl etherified melamine resin such as methylated melamine resin and butylated melamine resin is suitable. . As a commercially available product, specifically, SM
-975, SM-960 (trade name, manufactured by Harima Kasei Co., Ltd.), MW-30, MS-001, MX-002, MX
-705 (trade name of Sanwa Chemical Co., Ltd.), Melan-
21, Melan-2000 (trade name, manufactured by Hitachi Chemical Co., Ltd.), Uban 21R, Uban 22R (trade name, manufactured by Mitsui Toatsu Chemicals, Inc.), MX-408 (trade name, manufactured by Sanwa Chemical Co., Ltd.) and the like. . These melamine resins are used alone or in combination of two or more.

The adhesive for metal foil-clad laminates of the present invention contains the phenol resin in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the polyvinyl butyral resin. If the amount of the phenolic resin is less than 2 parts by weight, the solder heat resistance is poor,
If it exceeds 20 parts by weight, the tracking resistance is deteriorated. As commercially available products of the phenolic resin, specifically,
CJ2410 (trade name, manufactured by Matsushita Electric Works, Ltd.) and the like can be mentioned.

The metal foil-clad laminate adhesive of the present invention contains 3 to 30 parts by weight of blocked isocyanate with respect to 100 parts by weight of the polyvinyl butyral resin.
When the blocked isocyanate is contained in the above range, an adhesive having good tracking resistance and solder heat resistance can be obtained. The blocked isocyanate is
The isocyanate is made inert by reacting with a blocking agent which is an active hydrogen compound. As the blocking agent, for example, alcohols, phenols, oximes, active methylene compounds and the like are used. Among them, it is preferable that the blocking agent comprises at least one of phenol, alkylphenol and oxime. Specific examples of commercially available products include ZF3066 (trade name of Dainippon Ink and Chemicals, Inc.) as a phenol blocking agent, and ZA as an alkylphenol blocking agent.
-1161 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.)
Examples of the oxime blocking agent include ZA-1177 and 1160 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.). These blocked isocyanates may be used alone or in admixture of two or more.

Furthermore, the adhesive for metal foil-clad laminates of the present invention contains 0 parts of organic acid based on 100 parts by weight of polyvinyl butyral resin, epoxy resin, melamine resin, phenol resin, and blocked isocyanate. .0
It is contained in a proportion of 05 to 5 parts by weight. When the organic acid is contained in the above range, it is possible to prevent deterioration of solder heat resistance and the like even when an adhesive agent stored for a long period of time is used, and storage stability becomes good. Aromatic carboxylic acids and aliphatic carboxylic acids are suitable as the organic acid, and specific examples thereof include adipic acid and fumaric acid.

The adhesive for metal foil-clad laminates of the present invention further contains an organic solvent and the like, if necessary. The organic solvent is not particularly limited as long as it can dissolve the above-mentioned materials, and examples thereof include methanol, acetone, methyl ethyl ketone, and toluene, and these are used alone or as a mixture.

The adhesive obtained by the above composition is applied to a metal foil such as a copper foil. Metal foil-clad laminates such as phenol resin laminates using metal foil coated with this adhesive are
It has high tracking resistance and good solder heat resistance. Furthermore, even if a metal foil-clad laminate is produced using the adhesive that has been stored for a long period of time, performance such as solder heat resistance does not deteriorate.

[0017]

【Example】

Example 1 Denka Butyral 6000C manufactured by Denki Kagaku Kogyo Co., Ltd. was used as the polyvinyl butyral resin, and Epototo YDCN609 manufactured by Tohto Kasei Co., Ltd. was used as the epoxy resin.
As a melamine resin, SM-96 manufactured by Harima Chemicals Co., Ltd.
0 as a phenol resin, CJ manufactured by Matsushita Electric Works Ltd.
2410, ZA-1160 manufactured by Dainippon Ink and Chemicals, Inc. as a block isocyanate, adipic acid as an organic acid, and methanol, methyl ethyl ketone, and toluene at a mixing ratio of 1: 1: 1 by weight in an organic solvent. What was done was used.

100 parts by weight of polyvinyl butyral resin (hereinafter referred to as "part"), 20 parts of epoxy resin, 75 parts of melamine resin, 2 parts of phenol resin, 3 parts of blocked isocyanate and 0.01 part of organic acid are added to the above organic solvent. The solid content was uniformly dissolved to be 25% by weight to obtain an adhesive for metal foil-clad laminate.

Examples 2 to 3 Adhesives for metal foil-clad laminates were prepared in the same manner as in Example 1 except that the formulations shown in Table 1 were used.

Examples 4 to 6 Adhesives for metal foil-clad laminates were prepared in the same manner as in Example 1 except that ZA-1177 manufactured by Dainippon Ink and Chemicals, Inc. was used as the blocked isocyanate and the composition shown in Table 1 was used. Was produced.

Comparative Examples 1 to 3 Adhesives for metal foil-clad laminates were prepared in the same manner as in Example 1 except that the materials used and the composition were as shown in Table 1.

[0022]

[Table 1]

The obtained Examples 1 to 6 and Comparative Examples 1 to 3
Copper-clad laminates were prepared using the adhesive of Example 1, and the tracking resistance, solder heat resistance, and storage stability of the adhesive were evaluated. The peel strength was also measured.

Application of the adhesive and molding of the copper clad laminate were performed under the following conditions. First, the obtained adhesive is applied to one side of a copper foil having a thickness of 35 μm using a roll coater, and the temperature is 80 ° C.
After 3 minutes, it was dried at 150 ° C. for 5 minutes to form an adhesive layer having a thickness of 30 μm. Next, the adhesive layer surface of the copper foil coated with the above adhesive was disposed in contact with the prepreg on the outermost layer of the eight prepregs in which the paper base material was impregnated with the phenol resin to form a laminate. This laminated body has a temperature of 160 ° C. and a pressure of 100 kg.
/ Cm ² was heated and pressed for 60 minutes to obtain a copper-clad laminate having a thickness of 1.6 mm.

The above tracking resistance was measured as follows. A platinum electrode is placed 4 mm apart on the adhesive coated surface of the laminated plate from which the copper foil has been removed by etching, and 0.1% ammonium chloride aqueous solution is dropped at 30 second intervals while applying a predetermined voltage, and the laminated plate is ignited. The number of drops until this was recorded was recorded while changing the applied voltage. The voltage corresponding to 50 drops was determined from this value. It was measured up to 600V.

Based on JIS-C-6481, the solder heat resistance was floated on solder at 260 ° C., the time until swelling was measured, and 25 seconds or more was passed. The peeling strength was measured in the normal state based on JIS-C-6481.

With respect to the storage stability, the obtained adhesive is placed in a closed container, stored in a constant temperature bath at 40 ° C. for a predetermined number of days, and then the adhesive is applied and the laminated plate is formed under the above-mentioned conditions. It was The solder heat resistance of the laminate using the adhesive stored in a constant temperature bath at 40 ° C. was measured, and it was judged by the degree of decrease with respect to the initial solder heat resistance. The period during which the value of solder heat resistance after storage for a predetermined period was 70% or more of the initial value of solder heat resistance was defined as the number of stable storage days. The storage stability days of 20 days or more were accepted.

As shown in Table 2, in each of Examples 1 to 6, the tracking resistance was 500 V or more, the solder heat resistance was 32 seconds or more, and the storage stability days were also good. Each of the comparative examples had a high tracking resistance, but the storage stability was low.

[0029]

[Table 2]

[0030]

When the adhesive for metal foil-clad laminates according to claims 1 to 3 of the present invention is used, a metal foil-clad laminate having high tracking resistance and good solder heat resistance is obtained. Can be obtained. Furthermore, even if a metal foil-clad laminate is produced using the adhesive that has been stored for a long period of time, performance such as solder heat resistance does not deteriorate.

Claims (3)

[Claims] 1. An adhesive used for adhering a metal foil to a laminate, which comprises 10 to 40 parts by weight of an epoxy resin, 40 to 80 parts by weight of a melamine resin, and 100 parts by weight of a polyvinyl butyral resin. The resin is contained in a proportion of 2 to 20 parts by weight and the blocked isocyanate in a proportion of 3 to 30 parts by weight, and with respect to the polyvinyl butyral resin, the epoxy resin, the melamine resin, the phenol resin and the blocked isocyanate, the total weight is 100 parts by weight. And an organic acid in a proportion of 0.005 to 5 parts by weight, an adhesive for metal foil-clad laminates. 2. The adhesive for metal foil-clad laminates according to claim 1, wherein the blocking agent for the blocked isocyanate comprises at least one of phenol, alkylphenol and oxime. 3. The adhesive for a metal foil-clad laminate according to claim 1 or 2, wherein the organic acid is at least one of an aromatic carboxylic acid and an aliphatic carboxylic acid. Agent.