JPH01197906A - Lead wire for electronic component and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the discoloration resistance and the lubricity by using a hydrocarbon solvent as a base and containing specific quantities of mineral oil light lubricating oil base oil, phenol oxidation inhibitor and lanolin fatty acid ester respectively for rust preventive oil. CONSTITUTION:A plating layer with a conductor made of tin or tin-lead alloy is formed on a lead wire for an electronic component. Rust preventive oil containing phenol oxidation inhibitor with the concentration of 0.05-2wt.%, lanolin fatty acid with the concentration of 1.0-10wt.% and mineral oil light lubricating oil base oil with the concentration of 3-20wt.% is coated on this plating layer. The plating layer is protected from the contact with water and oxygen, thereby the discoloration of the plating layer is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lead wire for electronic components and a method for manufacturing the same.
In particular, the present invention relates to a lead wire for electronic components that has excellent discoloration resistance, lubricity, etc., and a method for manufacturing the same.

[Prior Art] Conventionally, solder-plated wires, which are formed by providing a plating layer of tin or tin alloy on a core conductor of copper or copper alloy, have been widely used as lead wires for electronic components and conducting wires for electronic devices. .

When this type of solder-plated wire is used as a lead wire for electronic components, it is cut to a predetermined size and then used for wiring between resistors that make up electronic components, such as electrical appliances. It becomes a part to be used.

[Problems to be Solved by the Invention] However, there is a phenomenon that such lead wires for electronic components turn yellow due to changes in temperature, increase in humidity, etc. during the inventory period and transportation period after manufacture. Yellowed wires for electronic components make it difficult to solder to connect electronic components, and also have a poor aesthetic appearance.

Therefore, in order to prevent this discoloration, it may be possible to apply a commercially available kerosene-based rust preventive oil. However, if a commercially available anti-corrosion oil is applied, although discoloration becomes less likely, resistance fluctuations are more likely to occur due to the metal ions of the fatty acid metal soap contained within.

Furthermore, if these metal ions adhere to the resistor body, there is a possibility that the resistor may be damaged. For this reason, commercially available kerosene-based rust preventive oils cannot be used to prevent discoloration of lead wires for electronic components.

The present invention has been made in view of such problems, and includes:
An object of the present invention is to provide a lead wire for electronic components that has high discoloration resistance and lubricity, and a method for manufacturing the same.

[Means for Solving the Problems] A lead wire for electronic components according to the present invention includes a conductor, a plating layer formed of tin or a tin-lead alloy on the conductor, and a barrier coated on the plating layer. This rust preventive oil is based on a hydrocarbon solvent, contains 3 to 20% by weight of a mineral oil-based light lubricating base oil, and contains 0% of a phenolic antioxidant.
．． 05 to 2% by weight, lanolin fatty acid ester 1.0
It is characterized by containing from 10% by weight.

The method for manufacturing lead wires for electronic components according to the present invention includes a step of plating a conductor with tin or a tin-lead alloy to form a plating layer, and a step of plating this composite wire at a concentration of 2 to 10% by weight and a temperature of 40 to 40%. 5 to 10% in an aqueous solution of tribasic sodium phosphate at 80°C.
A step of immersing for 0 seconds and then rinsing with water, and adding 3 to 20% by weight of mineral oil-based light lubricating base oil based on a hydrocarbon solvent.
It is characterized by comprising the step of applying a rust preventive oil containing 0.05 to 2% by weight of a phenolic antioxidant and 1.0 to 10% by weight of a lanolin fatty acid ester to the plating layer.

[Function] In the lead wire for electronic components according to the present invention, the conductor is plated with a plating layer made of tin or a tin-lead alloy, and this plating layer contains a phenol-based material having a concentration of 0.05 to 2% by weight. A rust preventive oil containing an antioxidant, a lanolin fatty acid ester at a concentration of 1.0 to 10% by weight, and a mineral oil-based light lubricating base oil at a concentration of 3 to 20% by weight is applied. Since the plated layer is coated with this antirust oil, it is protected from contact with water and oxygen, and discoloration of the plated layer is prevented.

Since this rust preventive oil does not contain metal ions that cause electrical resistance fluctuations, the lead wire for electronic components according to the present invention does not suffer from resistance fluctuations and performance deterioration.

On the other hand, in the method for manufacturing a lead wire for electronic components according to the present invention, first, the conductive wire is plated with a plating layer made of tin or a tin-lead alloy. Then, this composite wire is immersed in an aqueous sodium phosphate solution having a concentration of 2 to 10% by weight and a temperature of 40 to 80° C. for 5 to 100 seconds, and then washed with water. As a result, an anti-oxidation film is formed on the surface of the plating layer,
In addition, acid residues of the plating solution and polishing scum from the electroplating process are removed. Next, a rust preventive oil having the composition described above is applied to the plating layer. Since the plating layer has been previously treated with an aqueous solution of tribasic sodium phosphate, the rust-preventing effect of the rust-preventing oil is promoted, and an excellent rust-preventing effect can be obtained.

[Examples] Examples of the present invention will be described in detail below. Lead wires for electronic components have a plating layer formed around the conductive wire. This conducting wire is, for example, a wire of copper, copper alloy, copper-coated steel, or iron, and the plating layer is formed of a tin alloy containing 5% by weight of tin or lead.

Rust preventive oil is applied to the circumferential surface of this plating layer to form a film of rust preventive oil.

The rust preventive oil is based on a hydrocarbon solvent, contains 3 to 20% by weight of mineral oil-based light lubricating base oil, and 0% phenolic antioxidant.
．． 05 to 2% by weight, lanolin fatty acid ester 1.0
It contains 10 to 10% by weight, and does not contain metal ions such as fatty acid metal soaps, which cause electrical resistance fluctuations.

Below, the reason for blending each component of the rust preventive oil and the reason for limiting the amount added will be explained.

The base hydrocarbon solvent is a low-boiling kerosene obtained by removing the heavy parts of white kerosene, such as solvent kerosene, and has the characteristic of being easily dryable.

The content of the mineral oil-based light lubricating base oil is 3 to 20% by weight. If the content of the lubricating base oil is less than 3% by weight, the antirust effect will be low, and if it exceeds 20% by weight, the drying properties will be poor, making it unsuitable for use as lead wires for electronic components.

Phenolic antioxidants are the additives with the highest antirust effect. Moreover, the phenolic antioxidant does not contain metal ions that cause electrical resistance fluctuations. The reason why the content of the phenolic antioxidant is 0.05 to 2% by weight is that if the phenolic antioxidant is diluted more than this range, the rust prevention effect will be low, but if it is more concentrated than this range, the plating layer will be damaged. This is because it may turn yellow. Specifically, this phenolic antioxidant is DBPC (2,6
, di-tert-butyl-P-freezee.

Lanolin fatty acid ester has a content of 1.0 to 10% by weight. If the amount of lanolin fatty acid ester is less than 1.0% by weight, there will be no rust prevention effect, and if it exceeds 10% by weight, so-called stickiness will occur. This stickiness interferes with the process of wiring lead wires to the resistor and assembling it. An example of this lanolin fatty acid ester is Pentalan (trade name; manufactured by 70-Da Japan ■).

In the lead wire for electronic components configured in this way,
The additives (phenolic antioxidant and lanolin fatty acid ester) in the rust preventive oil that coats the plating layer are attracted to the plating layer in a polar form and adhere to it. A mineral oil-based light lubricating base oil is present to supplement the anti-rust effect of the additives.

In this way, the plating layer is coated with a film of rust-preventing oil that has a high rust-preventing effect, which prevents water and oxygen from adhering to the plating layer, resulting in yellowing of the plating layer during storage or transportation. is prevented. Furthermore, since this rust preventive oil does not contain metal ions such as fatty acid metal soaps that cause changes in electrical resistance, the rust preventive oil applied to the lead wires will not cause changes in electrical resistance.

Next, a method for manufacturing a lead wire for electronic components according to an embodiment of the present invention will be described.

First, a conductive wire made of copper, copper alloy, copper-coated steel, iron, or the like is plated with tin or a tin-lead alloy by electroplating to form a plating layer around the conductive wire.

Next, this composite wire was prepared at a concentration of 2 to 10% by weight and a temperature of 4%.
5 to 100% in an aqueous solution of tribasic sodium phosphate at 0 to 80°C.
After soaking for a second, wash with water. As a result, an antioxidant film layer is formed on the surface of the plating layer, and polishing scum and acid residues of the plating solution used in electroplating are removed.

The reason why the concentration of the tribasic sodium phosphate aqueous solution is limited to 2 to 10% by weight is that if the tribasic sodium phosphate aqueous solution is less than 2% by weight, the above effect will be small, whereas if it exceeds 10% by weight, the sodium triphosphate This is because it crystallizes and remains on the wire surface. Also, the temperature was set at 40 to 80°C.
This is because there is no effect below 80°C, and yellowing occurs due to the high temperature above 80°C. In addition, in order to obtain the above-mentioned effect, it is necessary to immerse the wire in the tribasic sodium phosphate aqueous solution for 5 seconds or more. Furthermore, if the plating layer is immersed in the tribasic sodium phosphate aqueous solution for more than 100 seconds, the treatment will be excessive and the discoloration resistance will deteriorate. Therefore, the immersion time should be 5 to 100 seconds.

Next, after washing this composite wire with water, 3 to 20% by weight of mineral oil-based light lubricating base oil is added to the hydrocarbon-based solvent.
A rust preventive oil containing 0.05 to 2% by weight of a phenolic antioxidant and 1.0 to 10% by weight of a lanolin fatty acid ester is applied to the plating layer. In this case, since the wire has been immersed in an aqueous solution of tribasic sodium phosphate in advance, a wave M layer for preventing oxidation is formed, and the acid residue of the plating solution is completely removed. The rust oil adheres to the surface of the clean plating layer, promoting the rust prevention effect of the rust preventive oil.

Next, the results of performance tests of discoloration resistance, lubricity, solderability, and resistance fluctuation for Examples of the present invention will be explained together with the test results of Comparative Examples.

Table 1 below shows Examples 1 to 7 and comparative examples 1 to 6 of lead wires for electronic components according to the present invention, and Table 2 shows examples 1 to 7 of lead wires for electronic components according to the present invention, and Comparative Examples 1 to 6 thereof. Examples 8 to 14 and comparative examples 7 to 12 in the case of pretreatment are shown. In each of the Examples and Comparative Examples, an annealed copper wire was used as a conducting wire, and the annealed copper wire was electroplated in a borofluoride bath to form a plating layer of a tin-lead alloy containing 95% tin and 5% lead. Next, in Examples 1 to 7 and Comparative Examples 1 to 6, a rust preventive oil having the composition shown in Table 1 was applied. Further, in Examples 8 to 14 and Comparative Examples 7 to 12, a rust preventive oil having the composition shown in Table 2 was applied after pretreatment with a tribasic sodium phosphate aqueous solution.

Each test was conducted on the lead wire thus obtained under the test conditions shown below.

(a) Color fastness: Evaluated by constant temperature constant temperature test.

That is, the lead wires of each example or comparative example were placed in an environment with a temperature of 85° C. and a humidity of 85%, and the discoloration status after 300 hours was visually compared.

(b) Lubricity: Comparison was made in terms of ease of collecting scum on the die during cutting work to join the lead wire to the resistor.

(c) Solderability: 25% rosin (pine resin) dissolved in ethanol is used as a flux, and the lead wire is immersed in this flux, and then immersed in a molten eutectic solder alloy. Comparisons were made based on quality.

(d) Resistance variability; determined by a so-called steam pressure test. In other words, apply anti-rust oil to the resistor body to apply to the lead wires, and then apply this to 2 atm and 121
After being immersed in a vortex at °C for 60 minutes and left at room temperature for 10 minutes, a load of 100% of the rating was applied for 60 minutes for 5 cycles to investigate changes in resistance before and after immersion.

The test results are shown in Tables 1 and 2. In Tables 1 and 2, ◎ indicates excellent performance, similarly ◯ indicates good, △ is acceptable, and × indicates poor.

As shown in Table 1, the lead wires of Examples 1 to 7 are superior to any of the lead wires of Comparative Examples 1 to 6 in terms of color fastness and resistance fluctuation. In addition, as shown in Table 2, Examples 8 to 14, which were pretreated under the conditions specified by the method of the present invention, are different from Comparative Examples 7 to 1, which are outside the conditions.
It has excellent color fastness compared to No. 2.

[Effects of the Invention] As explained above, according to the present invention, the rust preventive oil applied to the plating layer is based on a hydrocarbon solvent and has a concentration of 3.
20% to 20% by weight mineral oil based light lubricating base oil, concentration 0.0
5 to 2% by weight of phenolic antioxidant and a concentration of 1
．． Since it contains 0 to 10% by weight of lanolin fatty acid ester, its antirust effect is high and yellowing of the plating layer is effectively prevented.

Furthermore, since this rust preventive oil does not contain metal ions such as fatty acid metal soaps that cause electrical resistance fluctuations, the discoloration resistance can be improved without performance deterioration such as resistance fluctuations. Furthermore, it has excellent performance in terms of lubricity and solderability.

In addition, according to the method for manufacturing lead wires for electronic components of the present invention, the plating layer is treated with tribasic sodium phosphate before the rust preventive oil is applied, so the rust preventive oil applied to the plating layer is rust-proof. The effect is enhanced. Therefore, the color fastness can be further improved.

Claims (2)

[Claims] (1) It has a conductor, a plating layer formed of tin or a tin-lead alloy on the conductor, and a film of rust preventive oil applied on the plating layer, and this rust preventive oil is a hydrocarbon Based on the base solvent, it contains 3 to 20% by weight of mineral oil-based light lubricating base oil, 0.05 to 2% by weight of phenolic antioxidant, and 1.0 to 10% by weight of lanolin fatty acid ester. Characteristic lead wires for electronic components. (2) A process of plating the conductor with tin or tin-lead alloy to form a plating layer, and dipping this composite wire into an aqueous solution of tribasic sodium phosphate at a concentration of 2 to 10% by weight and a temperature of 40 to 80°C. A process of immersing for 100 seconds and then rinsing with water, and adding 3 to 20% by weight of a mineral oil-based light lubricating base oil and 0.05 to 2% of a phenolic antioxidant based on a hydrocarbon solvent.
1. A method for producing a lead wire for electronic components, comprising the step of applying a rust preventive oil containing 1.0 to 10% by weight of lanolin fatty acid ester to the plating layer.