JPS6164775A - Adhesive for additive chemical plating - Google Patents

Abstract

PURPOSE:The titled adhesive having powerful adhesiveness, resistance to plating chemicals, heat resistance, and good electrical characteristics, containing an acrylonitrile rubber and a Friedel-Crafts resin. CONSTITUTION:An adhesive for additive chemical plating containing an acrylonitrile rubber (usually of an acrylonitrile content of 18-52wt% and a Mooney viscosity of 25-90) and a Friedel-Crafts resin having the repeating units of the formula [wherein Ar is an (alkyl-containing) phenyl; R1 and R2 each are H or an alkyl; n is 0 or 1]. This adhesive has powerful adhesiveness, resistance to plating chemicals, heat resistance, and good electrical characteristics and is excellent as an adhesive for additive chemical plating. It is used for a printed circuit board, a decorative article, an electromagnetic shielding material, a moisture-proof sheet, an antistatic sheet, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to Aditep for chemical plating. More specifically, it relates to an adhesive with a composition containing acrylonitrile rubber and a specific free-sol Tarafluoro resin, and the adhesive has excellent chemical resistance, heat resistance, and electrical properties, and has strong adhesive properties. This is a plating adhesive.

(Prior Art) The additive chemical plating method is a method in which an adhesive layer is formed on an object to be plated, and then chemical plating is applied.

In the case of this method, the adhesive is required not only to have strong adhesive properties, but also to not be corroded by plating chemicals, and to have heat resistance. In the case of something like a circuit board, the solder plate is required to have good stability in a solder bath and good electrical properties.

A typical example of applying the Aditeb chemical Menke method is, for example, the production of printed circuit boards.

Therefore, the present invention will be described below with a focus on printed circuit boards.

Conventional printed circuit boards are based on glass Evokin substrates or paper phenolic substrates, and a desired pattern is printed on this copper-clad WIN board using photoresist or etching resist ink, which is then cured to form an acid-resistant resin layer. After that, the exposed copper foil portion is etched away using an aqueous ferric chloride solution or a cupric chloride aqueous solution to form a desired pattern.

However, in this method, the necessary W4 foil portion normally occupies only about 40% of the copper foil area of the initial copper-clad laminate, and the remainder is removed by etching, so resources are consumed. Not only is it wasted and economic losses are inevitable, but there is also the problem of causing pollution when the etching solution is discharged.

In addition, side etching thins the circuit, making it difficult to form fine patterns, but this is due to the miniaturization of equipment in recent years
This is inconvenient for high-density wiring, which is required in response to higher performance. In addition, when manufacturing a through-hole plating printed circuit board, chemical plating and electroplating are applied to the entire surface of the substrate including the inner surface of the hole, and the required thickness of fIN is deposited. The inner wall of the through-hole and the necessary circuit parts are covered using a method such as the retaining method or the retaining method, and the copper foil from non-circuit parts is removed by etching to create the desired circuit. However, in addition to the above-mentioned drawbacks, this method also has other problems, such as a complicated process and the need for electroplating equipment.

For these reasons, the aditeb chemical plating method, which has improved the above-mentioned problems, is attracting attention.

Unlike conventional methods, the Aditeb chemical plating method has fewer problems with pollution due to thinning of the circuit due to side etching and discharge of etching solution, and is a method that meets the requirements for energy and resource conservation.It is a simple process and inexpensive. Moreover, it is a method for producing highly reliable printed circuit boards.

In other words, it is a method of forming circuits by directly applying chemical steel plating on the laminate and in the holes in the through holes.More specifically, this method uses an adhesive that can firmly bond metal onto the laminate. After forming a layer of adhesive and curing it by heating, through-holes are opened, and the process of oxidizing and roughening the fat adhesive - forming a thin chemical steel plating on the entire surface by chemical copper plating - plating resist application process - electrical steel plating process - plating Resist stripping process - quick etching process of chemical steel plating on areas not plated with electrical steel, or (b)
Menkiresist coating process on adhesive surfaces other than circuit parts
Oxidation roughening process of the circuit part - This is a process of chemical copper plating on the adhesive in a chemical copper plating bath to form the necessary circuit and simultaneously deposit metal into the through holes.

According to this method, as mentioned above, the manufacturing process is simple, the coverage of the chemical copper plating on the through holes is good, and even when the hole diameter is small and the board thickness is large, copper is plated uniformly inside the through holes. This method has advantages such as being able to pass through 1&density wiring because the accuracy of forming the wiring pattern is determined by the accuracy of the resist.

By realizing these advantages of the Aditep chemical plating method,
In order to manufacture printed circuit boards with high reliability, various adhesives have been developed. In other words, the adhesive plays an extremely important role in the quality of the printed circuit board, and in other words, it can be said that the quality of the printed circuit board is determined by the plating solution and the adhesive.

Conventionally, this adhesive has been prepared using, for example, a composition containing acrylonitrile rubber and a phenolic resin, a gold rfA oxide such as zinc white or magnonium oxide, a filler such as calcium carbonate or finely powdered silica, and a composition such as methyl ethyl ketone. An adhesive solution uniformly dispersed in a welding agent has been used.

However, as mentioned above, with the miniaturization and higher performance of devices, the conditions of use have become increasingly severe, and the requirements for heat resistance and durability of adhesives have also become more sophisticated. Such adhesives maintain strong adhesion to insulating substrates even under the harsh processing conditions used to create printed circuits, i.e., when the circuit width is narrow, and are suitable for use in solder baths. It should not cause blistering or peeling when subjected to IR, should not be eroded by plating chemicals, and should not interfere with machinability such as drilling.
In addition, good electrical properties such as insulation resistance between circuits are required, but it has not always been possible to obtain stable adhesive performance with adhesives made from conventional adhesive compositions.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a 7-date chemical plating adhesive that has excellent heat resistance, adhesive properties, electrical properties, and chemical resistance.

[Means for solving problems]

The present invention utilizes acrylonitrile rubber and the general formula (wherein, At
is a phenyl group which may have an alkyl group, R1 and R2 are each a hydrogen atom or an alkyl group, and n is not 0 or 1. This is an adhesive for Aditeb chemical plating, which is characterized by:

The acrylonitrile rubber used in the present invention may be one mainly composed of a copolymer of 7 acrylonitrile and butadiene. Usually, the acrylonitrile rubber is 18 to 5 acrylonitrile.
2% by weight, preferably 35-45% by weight, and a Mooney viscosity of 25-90, preferably 40-80. Crosslinking is performed using a known crosslinking agent such as sulfur or hydrazine, and other components used are those added to ordinary acrylonitrile rubber.

The Friedelkraff resin used in the present invention has a repeating unit represented by the general formula (+).

In this specification, the alkyl group preferably has 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, 15O-propyl, and n-butyl.

The Friedel Krach resin has a softening point of 70 to 1
Preferably, the temperature is 30°C.

The Friedel Krach resin is hexamethylenetetramine (methylene*+a by hexamine).

The resin, which is preferably epoxy crosslinked, is produced by a Friedel-Track reaction; for example, a resin in which phenol and a,α°-dimethoxoparaxylene are bonded by a free-sol Tarafluor reaction is Its structural feature is that methylene bonds are replaced by paraxylene bonds, compared to the case of ordinary novolac-type phenolic resins. Characteristic features resulting from this structural feature include slow oxidative deterioration at methylene crosslinks, resulting in long-term heat resistance stability, and low content of phenolic hydroxyl groups, resulting in low water absorption and dimensional stability. It has excellent properties such as durability, chemical resistance, and electrical properties.

The composition of the adhesive includes acrylonitrile rubber and the free sol Tarafluoro resin in a ratio of 2:8 to 8:2, preferably 3 to 7:3. If necessary, a vulcanizing agent such as sulfur, filler such as calcium carbonate, finely powdered chlorine powder, etc. may be added. If the content of the free sol fluorine resin exceeds 70%, the plating performance etc. will deteriorate, and If the acrylonitrile rubber content exceeds 70%, there is a risk that heat resistance will decrease.

The adhesive of the present invention contains 70 to 100 parts by weight (especially 80 to 90 parts by weight!) of acrylonitrile rubber and Friedeltrack resin.
(amount parts) is preferably contained.

A practical method for preparing the adhesive is to knead it with a cold mixing roll or the like, then dissolve it in methyl ethyl ketone, xylene, etc. and form it into a face.

The adhesive of the present invention is used as an adhesive for aditeb chemical plating, and there are no particular restrictions on the object to be plated as long as the adhesive of the present invention can adhere to it (the specific material of the material). Examples include plastics (polyethylene,
Thermoplastic resins such as nylon, vinyl chloride, acrylic resins,
or thermosetting TL resin such as melamine resin, phenol resin, epoxy resin, polyester, polyurethane, etc.),
Examples include metals (iron, gold, silver, copper, aluminum, etc.), and there are no particular restrictions on the shape of the object to be plated.

Examples of objects to which the adhesive of the present invention can be used include printed circuit boards, ornaments, electromagnetic shielding materials, moisture-proof sheets, static elimination sheets, and the like.

(Effects) The adhesive of the present invention has strong adhesive action, plating chemical resistance, heat resistance, and good electrical properties, and is excellent as an adhesive for Aditep chemical plating.

The following is a description based on Examples and Reference Examples.

Reference Example (Hofufu A) 940 g (10 moles) of phenol and 1112 g (6.7 moles) of p-xylene dimethyl ether were mixed in a flask. A catalytic amount of aluminum chloride was added to this mixture and the resulting mixture was heated to reflux with stirring. After the initial exothermic reaction has finished, the methanol and excess phenol produced by the reaction are evaporated to 130 ml.
It was removed by distillation over a temperature range of ~200°C. After the distillation was completed, the product was cooled to 160°C, poured into a tray, and solidified. The resulting IM fat was a solid with a softening point of 95°C.

(Resin B) 1080 g (10 mol) of p-cresol and C3,
1427 g (6.7 mol) of 5-trimethoxymesitylene were mixed in the flask. A catalytic amount of aluminum chloride was added to this mixture and the resulting mixture was heated to reflux with stirring. After the initial exothermic reaction had ended, methanol and excess p-cresol produced by the reaction were removed by distillation over a temperature range of 150-220°C. At the end of the distillation, the product was cooled to 160° C. and poured into a tray to solidify. The obtained resin is 1
It was a solid with a softening point of 0.3°C.

Examples 1 to 2, Comparative Examples 1 to 4, and Experimental Example 1 Table 1 shows the formulations and properties of Example 1.2 and Comparative Example 1.2.3.4. After mixing with a mixing roll, it was dissolved in 500% methyl ethyl ketone to form a face adhesive. In addition, for characteristic evaluation, the adhesive coating surface was etched with oxidizing chromium fiM, and then chemical plating was performed to create a copper-plated laminate with a copper foil thickness of 35 μm.
It was conducted in accordance with JIS-C6481.

Written amendment to the Leeward Nahaku procedure (Own ship dated lθ/30/1980!, Indication of the case, Patent No. 186850 of 1983 2, Name of the invention, Aditeb chemical plating adhesive 3, Person making the amendment, Relationship with the case) Patent Applicant Name: Nitto Electric Industry Co., Ltd. 4, Agent ■541 Address: 406 Nie Life Hirano-cho, 4-53-3 Hirano-cho, Higashi-ku, Osaka Telephone: (06) 227-1156 Column 6 of ``Explanation'', contents of the amendment (υ Corrections in Table 1, pages 14 and 15 of the specification).

Claims (3)

[Claims] (1) Acrylonitrile rubber and general formula▲Mathematical formula, chemical formula, table, etc.▼ (In the formula, Ar is a phenyl group that may have an alkyl group, R_1 and R_2 are each a hydrogen atom or an alkyl group, n indicates 0 or 1) Aditev chemical plating adhesive characterized by containing a Friedel-Crafts resin having a repeating unit represented by the following. (2) The Aditev chemical plating adhesive according to claim (1), wherein the blending ratio of acrylonitrile rubber and Friedel-Crafts resin is 2:8 to 8:2 (weight ratio). (3) The softening point of Friedel Crafts resin is 70 to 130
The Aditev chemical plating adhesive according to claim 1 or 2, wherein the temperature is .degree.