JP2546361B2 - Non-solderable conductive metal with fluorine-containing silane compound adhered to the surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a conductive metal material having a fluorine-containing silane compound adhered to the surface thereof and having no solderability.

<Problems of Prior Art> Conventionally, conductive metal materials have been widely used mainly in copper for electric wires, printed circuit boards and other electronic industry fields. In this case, various methods have been developed as a method for joining metals, but soldering is the most common method.
However, when joining metals by soldering, the solder may flow to a portion other than the joined portion and cause a short circuit, which is a serious problem particularly in a field requiring high precision such as an integrated circuit. As a countermeasure, a method of coating with a hydrocarbon resin is used for soldering, but it is difficult to miniaturize because the resin layer is thick, and the heat resistance of the resin is low, and the adhesion to the substrate There is a problem such as bad, not repelling solder sufficiently. When coated with a fluororesin, there is no problem in solder repelling property and heat resistance, but there is a problem in that the adhesion to the base metal is inferior to the hydrocarbon resin.

<Knowledge for Solving Problems> The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, treat the surface of the conductive metal material with the fluorine-containing silane compound represented by the general formula (I) or (II). As a result, we have obtained the knowledge that the above problems can be solved.

That is, the present invention <Configuration of the Invention> has the general formula _{Rf (CH 2) n Y (} CH 2) m SiX 3 (I) [wherein Rf is C
_1-20 perfluoroalkyl group, n, m is an integer of from 0 to 3, Y is _{-CH 2 -, - CH 2 O} -, - NR -, - CO 2 -, - CONR
-, - S -, - SO 3 -, - SO 2 NR- (R is H or C
_1-8 alkyl groups), X is Cl, Br, OC
And a fluorine-containing silane compound represented by the formula [H ₃ , OC ₂ H ₅ ], which is adhesively bonded to the surface.

In the fluorine-containing silane compound represented by the general formula (I) according to the present invention, Rf is a C _1-20 perfluoroalkyl group, the alkyl group may be saturated or unsaturated, and a straight chain type, Any of those having a branched chain may be used. Further, there may be an appropriate substituent, and an ether bond may be interposed in the middle. Y is a linking group linking the perfluoroalkyl group Rf and a tri-substituted silyl group SiX ₃ via a methylene _{chain, -CH 2 -, - CH 2} O -, - NR -, - CO 2
-, - CONR -, - S -, - SO 3 -, - selected from among SO ₂ NR-. Here, R is H or a C _1-8 alkyl group. The alkyl group may be saturated or unsaturated, and may be linear or branched. The alkyl group may have a suitable substituent, but is preferably one without a substituent.

As the fluorine-containing silane compound in the present invention, any compound represented by the general formula (I) is effective.
A compound represented by the general formula C ₈ F ₁₇ SO ₂ NR ′ (CH ₂ ) ₃ SiX ₃ (II) is particularly preferable. In the general formula (II), R'is C
It is an alkyl group of _{1 to 5} , and the alkyl group may be saturated or unsaturated, and may be linear or branched. Although suitable substituents may be present, those without substituents are preferred.

The fluorine-containing silane compound in the present invention has its trihalosilyl group and trialkoxysilyl group reacted with water to form a trihydroxysilyl group, which is dehydrated and condensed with a hydroxyl group existing on the surface of the metal material, or a hydrogen bond is formed. Even if a metal material that does not have a hydroxyl group on the surface is strongly adsorbed, the perfluoroalkyl groups arranged on the surface at the same time show water and oil repellency and repel solder liquid or grease contained in it. Have
That is, there is no adhesion to solder, and this has the effect of preventing the solder from adhering to the metal surface.

This effect is greater in the compound represented by the formula (II), and the sulfonamide bond in the compound represented by the formula (II) facilitates the orientation of the perfluoroalkyl group to the surface and further improves the adhesion to the metal material. To further improve the non-adhesiveness of the solder.

The metal material to which the present invention is applied is not particularly limited. In addition to copper, which is a typical conductive material that is commonly used,
It is also possible to apply to gold, silver, iron, aluminum, or various alloys. The shape of the metal material may be linear or plate-like, and is not affected by the shape or size at all.

The amount of the fluorine-containing silane compound attached varies depending on the specific surface area of the metal material, but it is 10 ^-6 to the surface of the metal material.
It is preferably between 20% by weight.

If it is less than 10 ^-6 % by weight, the water and oil repellency will not be effective, and
When it is at least wt%, there is no significant change in characteristics as compared with the case where it is less than that.

The reflectance of the surface of the metal material according to the present invention is almost the same as that of the above-mentioned fluorine-containing silane compound which is not adhered and bonded, and the gloss of the surface is not lost.

The surface treatment method of this metallic material is carried out by applying a solution containing the fluorine-containing silane compound represented by the formula (I) or (II) to the above metallic material. As the coating method, an ordinary coating method such as a dipping method, a spray method or a brush coating method is used. As the solvent for preparing the solution of the fluorine-containing silane compound, organic solvents such as halogenated hydrocarbons, alcohols and ethers are preferable, and anhydrous or, if necessary, those to which a small amount of an aqueous solution of amine or acid is added are used. To be done. The amine used here may be any of primary amine, secondary amine, and tertiary amine, and primary amine is particularly effective. As the acid, inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid, and organic acids such as formic acid, acetic acid, oxalic acid and toluenesulfonic acid can be used.

In an aqueous solution of these amines or acids, water hydrolyzes the trihalogenosilyl group or trialkoxysilyl group of the fluorine-containing silane compound to form a trihydroxysilyl group —Si (OH) ₃ and It has a function of dehydrating and condensing with a hydroxyl group or strongly adsorbing a metal material having no hydroxyl group on the surface. Acids and amines act as catalysts that accelerate this hydrolysis and dehydration condensation.

The concentration of these amines or acids is 15% of the total amount of the processing solution.
Amounts of less than or equal to wt%, preferably about 0.05 to 5 wt% are suitable.

The treatment temperature when treating the metal material with these fluorine-containing silane compounds varies depending on each solvent, but is performed in the temperature range from room temperature to the boiling point of the solvent.

Further, when using an anhydrous solvent, or when treated at room temperature, if necessary 60 to 150 ℃, preferably 80 to 1
Dried at 30 ° C. These treatments are necessary in order to more firmly bond the fluorine-containing silane compound with the metal material.

<Effects of the Invention> When the fluorine-containing silane compound according to the present invention uses a conductive metal material strongly bonded to the surface, there is no adhesiveness to solder even if the solder flows out to the outside of the metal joint, The spilled solder is very easily removed. Therefore, the metallic material according to the present invention is most suitable for use in an integrated circuit which requires particularly high precision.

<Example> Example 1 A fluorine-containing silane compound C _{7 was} added to a copper plate (100 mm x 50 mm x 1 mm).
0.5 wt% ethanol solution of F ₁₅ CO ₂ (CH ₂ ) ₃ Si (OCH ₃ ) ₃ (including 0.3 wt% of 10% sulfuric acid aqueous solution) was applied, and 7 × 10 ⁻⁴ wt% of fluorine-containing silane compound adhered. A copper plate was obtained. When tin-lead alloy solder was melted and dropped on this copper plate, the solder adhered to the surface of the copper plate after cooling, but immediately peeled off when tapped. Example 2 As a fluorine-containing silane compound ^Was treated in the same manner as in Example 1 to give 6 × 10 ⁻⁴ % by weight.
A copper plate having the above-mentioned fluorine-containing silane compound attached thereto was obtained.

When the adhesion of the solder to this copper plate was evaluated in the same manner as in Example 1, the solder hardly adhered to the copper plate and was peeled off immediately when it was lightly touched.

Comparative Example 1 The same test as in Example 1 was conducted using an untreated copper plate, but the solder adhered strongly to the copper plate and did not peel off even when tapped strongly.

Claims (3)

(57) [Claims] 1. A general formula Rf (CH ₂ ) _n Y (CH ₂ ) _m SiX ₃ (I)
[Wherein Rf is a C _1-20 perfluoroalkyl group, n, m
Is an integer of 0 to 3, Y is _{-CH 2 -, - CH 2 O} -, - NR -, - C
_{O 2 -, - CONR -,} - S -, - SO 3 -, - SO 2 NR- (R is H
Or a linking group such as a C _1-8 alkyl group), X is Cl,
A fluorinated silane compound represented by Br, OCH ₃ , OC ₂ H ₅ ] is adhesively bonded to the surface of the conductive metal material having no adhesion to soldering. 2. A fluorine-containing silane compound having a general formula of C ₈ F ₁₇ SO ₂ NR ′ (CH ₂ ) ₃ SiX ₃ (II) (wherein R ′ is C
The conductive metal material according to claim _{1, wherein} the alkyl group is _{1 to 5} , and X is a compound represented by Cl, Br, OCH ₃ , OC ₂ H ₅ ). 3. A fluorine-containing silane compound represented by the general formula (I) or (II) is added to the surface of a conductive metal material in an amount of 10: 1.
The conductive metal material according to claim 1, which has an adhesive bond of ^{-6 to} 20% by weight.