KR101696796B1 - A method for plating copper alloy with tin - Google Patents

Abstract

The present invention relates to a tin plating method for a copper alloy material. The use of the tin plating method of the copper alloy material according to the present invention not only reduces the amount of black dust generated on the tin plating surface but also suppresses the occurrence of stains on the surface and improves the gloss have. The tin plating method of the copper alloy material according to the present invention exhibits an excellent effect not only in suppressing generation of black powder, improving gloss, reducing occurrence of stains, but also in productivity.

Description

METHOD FOR PLATING COPPER ALLOY WITH TIN BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a tin plating method for a copper alloy material. The present invention particularly relates to a tin plating method of a copper alloy material characterized by using an air stream (air and mixed state of mist) mist spraying method in a flux step of a tin plating method.

Tin (Sn) is a thin, brightly lustrous metal. Tin is harmless to the human body and acts as a protective anode from a sacrificial anode. The tin-plated steel sheet using such properties is widely used in food cans and the like.

On the other hand, copper alloy materials are mainly used as materials for electronic parts and semiconductor parts such as integrated circuits (IC) and lead frames in electronic materials and semiconductor fields. The parts made of the copper alloy material are placed in an environment where they are exposed to air or oxidized at high temperatures during transportation and storage during the manufacturing process of the electronic product and the oxidation film is easily formed on the surface of the metal. But also the contact resistance of the terminal may be adversely affected. Therefore, thin film processing is often performed with tin or a tin alloy as a final step of manufacturing passive components such as capacitors and transistors.

When tin plating is performed on the copper alloy material, crystals of the needle-shaped structure, that is, whiskers are generated, which causes disadvantage that conduction becomes poor due to an increase in resistance. In the past, tin plating has been used by adding a small amount of heavy metals such as lead. For example, Japanese Patent Laid-Open Publication No. 2009-263785 discloses a metallic material for a connecting part, which comprises a copper wire or copper alloy core wire as a base material and a copper-tin alloy layer substantially consisting of copper and tin on its surface, The copper-tin alloy layer contains at least one selected from the group consisting of zinc, indium, antimony, gallium, lead, bismuth, cadmium, magnesium, silver, gold and aluminum in a mass ratio of 0.01% By weight or less based on the total weight of the metal parts.

However, lead, a heavy metal harmful to humans and the environment, is a cause of pollution and is being replaced by lead-free plating in order to reduce pollution caused by it.

On the other hand, the surface of the tin or tin alloy plated on the copper alloy material should maintain a low contact resistance and be kept free from oxidation film in order to facilitate soldering (soldering) in the subsequent process. Korean Patent Laid-Open Publication No. 10-2008-0049768 discloses an antioxidant which is excellent in antioxidation performance during heating and humidification by treating tin or a tin alloy and exhibits good solder wettability, wherein two or more phosphonic acid groups And contains a compound and / or a salt thereof not containing an ester bond in the molecule and a phosphoric acid ester having an alkyl group of 6 to 10 carbon atoms, and a water-based antioxidant of the tin and tin alloy.

However, even when an antioxidant is substantially used, an oxide film is often formed in a plating process with a tin or a tin alloy of a copper alloy. For example, in a flux process during a tin plating process, a chemical such as an antioxidant is used for a long time , It is often the case that an oxide film is formed on the surface of the tin plating material due to the loss of the ability to remove the oxide film due to the aging of the antioxidant.

In addition, medicines such as antioxidants used in the tin plating process cause stains on the plated surface. This smear causes appearance defects on the plating surface after passing through the reflow.

Therefore, it is necessary to develop a tin plating method in which tin oxide is hardly generated and unevenness does not occur even after the tin plating process of the copper alloy material is completed.

Through the present invention, it is intended to suppress or control the formation of black dust (smut) which is an oxide remaining on the tin surface after the tin plating process of the copper alloy material. In addition, by preventing the generation of stains due to the antioxidant on the surface of the plating layer through the present invention, it is intended to simultaneously solve the problems of deterioration of the quality of the plated product and deterioration of the productivity such as facility cost of the plating process.

The present invention relates to a tin plating method for a copper alloy material, Electrolytically degreasing the copper alloy material to be tinned, pickling the electrolytically degreased copper alloy material, immersing the pickled copper alloy material in a copper plating solution A step of pre-dipping the copper-plated copper alloy material in the pre-dipping solution, a step of tin plating the pre-dipped copper alloy material, a step of dipping the tin-plated copper alloy material at 5 to 30 DEG C for 5 to 10 seconds Treating the resulting copper alloy material at 500 ° C to 600 ° C for 1 minute to 3 minutes to reflow the resulting copper alloy material at a temperature of 100 ° C to 300 ° C And then drying for 1 minute to 5 minutes, wherein the antioxidant in the fluxing step is applied in a mist spraying method to a tin plating method of a copper alloy material. The method may further comprise the step of automatically inspecting the dried copper alloy material after the drying step.

The copper alloy material may be selected from pure copper, brass, phosphor bronze, LF material, P-194, PMC26, or PMC102.

The electrolytic degreasing may be performed by a bipolar electrolytic degreasing method.

In addition, the pickling step may be performed by an acid immersion treatment and an activation treatment method.

The copper plating solution may have a ratio of copper sulfate to sulfuric acid of 1: 1 to 1: 2.

In the flux step, the antioxidant may be selected from phosphoric acid, sodium triphosphate, sulfurous acid, methanesulfonic acid, or polyglycol ethers. The antioxidant may preferably be a polyglycol ether. The concentration of the antioxidant may range from 8 to 12% by volume. The mist spray can be injected at a pressure of 1 to ² kg / cm 2 the antioxidant and the air through the fluid nozzle. The mist spray may be formed by forming an antioxidant atmosphere in a cell where flux is generated.

According to the present invention, it is possible to provide a tin plating method of a copper alloy material in which almost no black powder (smut) as an oxide after tin plating is generated. Specifically, according to the present invention, the antioxidant is applied to the surface of the tin plating to inhibit or control the formation of black dust (smut), which is an oxide, to reduce gloss, reduce solderability, and prevent whiskers. Further, even if the antioxidant is applied to the object to be plated for a long time, the contamination does not occur and the secondary contamination can be prevented, so that the tin plating facility does not occur.

FIG. 1 is a conceptual diagram illustrating that black powder, which is tin oxide produced on the surface of a tin-plated copper alloy material in the conventional method, is piled up in a subsequent process, causing problems.
FIG. 2 is a photograph for confirming whether or not stains have occurred in the samples 1 to 7 according to Example 1 and Comparative Examples 1 to 6 in Test Example 1. FIG.
Fig. 3 is a photograph comparing the amount of black dust produced in Test Example 2 with respect to samples 8 and 9 according to Example 2 and Comparative Example 7. Fig.
4 is a photograph showing the results of the corrosion resistance test on Samples 8 and 9 according to Example 2 and Comparative Example 7 in Test Example 2. Fig.
5 is a photograph showing the results of the heat peeling test for Samples 8 and 9 according to Example 2 and Comparative Example 7 in Test Example 2. Fig.
Fig. 6 is a SEM photograph comparing the plating tissues of Samples 8 and 9 according to Example 2 and Comparative Example 7 in Test Example 2. Fig.
7 is a photograph comparing the amount of black dust (smut) generated in Example 3, Comparative Example 8 and Reference Example 1 in Test Example 3, and an FIB cross-sectional image.
8 is a photograph and a graph showing the results of measurement of the surface roughness of the surface of the surface of the substrate in Example 3, Comparative Example 8 and Reference Example 1 showing smoothness.

The present invention relates to a tin plating method for a copper alloy material, in which generation of black powder (smut) as an oxide after tin plating on a copper alloy material is suppressed, and unevenness is not generated.

The copper alloy material to be subjected to tin plating in the present invention is used in a broad sense and includes both copper alloy and pure copper unless otherwise specified. Examples of non-limiting copper alloy materials include pure copper, brass, phosphor bronze, LF material, P-194, PMC26, PMC102 And the like.

A tin plating method of a copper alloy material according to the present invention includes the steps of electrolytically degreasing a copper alloy material to be tinned, pickling the electrolytically degreased copper alloy material, immersing the pickled copper alloy material in a copper plating solution A step of pre-dipping the copper-plated copper alloy material in a pre-dipping solution, a step of tin plating the pre-dipped copper alloy material, a step of dipping the tin-plated copper alloy material at 5 to 30 DEG C for 5 seconds Treating the resulting copper alloy material at 500 to 600 DEG C for 1 minute to 3 minutes to reflow the copper alloy material; and subjecting the obtained copper alloy material to a temperature of 100 DEG C to 300 DEG C Lt; 0 > C for 1 minute to 5 minutes, And a mist spraying method is applied in the flux step. The tin plating method of the copper alloy material may further include a step of automatically inspecting the copper alloy material dried after the drying step.

Specifically, the electrolytic degreasing (cleaning) step in the tin plating method of the present invention is a step of electrolytically removing other contaminants such as oxides and oils on the surface of the copper alloy material. In general, if electrolytic degreasing or degreasing is insufficient, poor adhesion, poor gloss, coarse plating, fatigue, bulging, and brittleness may occur. As the electrolytic degreasing method, a general electrolytic degreasing method can be used. For example, negative electrolytic degreasing, bipolar electrolytic degreasing, PR electrolytic degreasing and the like may be included. In the present invention, the anodic electrolytic degreasing may preferably be performed at 50 ° C by applying a heating system.

Next, the pickling step is a step of removing surface contaminants such as oxides and hydroxides which are not completely removed in the electrolytic degreasing step, using an acidic aqueous solution. The types of pickling include electrolytic pickling, acid dipping and activation treatments. In the present invention, acid pickling and an activating treatment method are preferred.

Acid dipping and activation treatment is a method of activating by removing the oxide film on the surface of the material to be plated, and is performed by immersing the tin-plated copper alloy material in 5 to 10 volume% of sulfuric acid for 3 to 15 seconds . The scale produced on copper or copper alloy is mainly copper (I) oxide, copper (II) oxide or copper (II) oxide or a combination thereof. To remove this, sulfuric acid mainly containing dichromate is used . However, in the dipping of the finishing material, about 5 to 20% by volume of sulfuric acid can be immersed. Or bright dipping (or cleanliness finish), is widely used for copper or copper alloys. That is, a smut for reducing the surface smoothness caused by immersing the object to be treated with a scale or the like in a solution obtained by adding nitric acid and / By the brightness treatment of It is a way to make a brilliant surface. Liquid nitrate (72cc / L), hydrochloric acid (2cc / L) and water (491cc / L) are used as the clarity solution. . The liquid of this system has extremely high reactivity, is very susceptible to the treatment time / treatment temperature, and has a harmful gas such as a nitrite gas. In addition, since it contains an oxidizing agent such as nitric acid, it is also necessary to activate it with a dilute hydrochloric acid solution or a dilute sodium cyanide solution after the treatment.

Next, the copper plating step is a step for smoothing the surface of the base material such as the copper alloy material after pickling to improve the adhesion and smoothness of the tin plating in order to prevent peeling of the tin plating layer. In particular, if a brass material is not plated, it is necessary to perform a copper plating step because defective gloss, coarse plating, peeling of the plating and defective black spots due to zinc elution may occur. As the copper plating solution, a mixed solution of copper sulfate and sulfuric acid may be used. For example, a mixed solution of 200 g / L of copper sulfate and 50 g / L of sulfuric acid can be used. To the mixed liquid The addition of a commercially available polish can be used to achieve leveling and polishing with a high degree of flexibility. However, the above-mentioned plating liquid has drawbacks such as poor gloss and leveling of the low current density portion, and cooling of the plating liquid in summer. These defects can be solved by using a copper plating solution having a composition of 70 to 100 g / L of copper sulfate and a copper sulfate to copper sulfate ratio of 1: 1 to 1: 2, preferably of 100 to 190 g / L of sulfuric acid. In the copper sulfate plating solution having a high concentration of copper sulfate and a low concentration of sulfuric acid, the copper layer is matte at the low current density portion and the matt charge is transferred to the high current density portion as the temperature rises and the uniform electrodeposition property and the coating power are not good. The plating solution is a low-concentration copper sulfate plating solution having a low concentration of copper sulfate and a high sulfuric acid concentration. As the copper plating solution used in the present invention, a low-concentration copper sulfate plating solution having 90 g / L of copper sulfate and 180 g / L of sulfuric acid is very excellent in uniform electrodeposition property and is used for hole plating in a double-sided substrate of a printed circuit.

Subsequently, the preliminary dipping step is carried out in the same manner as described above, It is a step to cleanly remove copper plating chemicals and to maximize compatibility with tin plating chemicals. The copper alloy material obtained in the previous step is pre-immersed in the pre-immersion liquid. The preliminary immersion liquid may be selected and used by a person skilled in the art, among the antioxidant drugs used as the tin plating solution, so long as it does not affect the tin plating solution contamination. For example, it is preferable to dope the copper alloy material obtained in the previous step to 10 vol% of an organic acid such as methane sulfonic acid (MSA) for about 1 to 5 seconds. However, if the pre-dipping is not performed properly and the copper ions are introduced into the tin plating agent while the copper ions remain on the surface of the original material, the oxidation of the tin plating agent proceeds more quickly and affects the quality of the tin plating and the life of the tin- You need to be careful because it can go crazy.

The tin plating step is a step in which tin plating, which is the core of the tin plating process, is substantially carried out. Through the tin plating, the effect of increasing the corrosion resistance, imparting or improving the solderability, and imparting the self-lubricating property can be obtained. Generally, tin plating is performed at a temperature of 20 캜 to 35 캜 for 2 minutes to 4 minutes. Tin plating may be carried out according to methods generally known in the art, and as a non-limiting example, a mixture of 20 to 32% by volume of the organic acid MSA, 28 to 44 g / L of the organic acid and 70 to 130 ml / Using a copper alloy material obtained in the previous step as a tin electrode and a negative electrode, electricity was heated to 800 to 1500 A .

Next, the flux step is a step of removing the oxide film on the metal surface, which is the base material, to prevent the reoxidation of the metal during heating during the soldering operation and to lower the surface tension of the melting soldering, thereby improving the spreadability of the soldering . The fluxing step of the present invention is carried out by spraying the antioxidant in a mist manner at 5 to 30 DEG C for 5 to 10 seconds.

As the antioxidant that can be used in the above-mentioned flux step, for example, phosphoric acid, sodium triphosphate, sulfurous acid, methanesulfonic acid or polyglycol ether can be used. It is preferable that the antioxidant hardly generates black dust and does not cause stain on the surface of the tin plating layer.

In the present invention, an antioxidant containing polyglycol ether as a component is preferably used as the antioxidant. The polyglycol ether is It is an antioxidant of tin or tin alloy plating that has a relatively low temperature effect and is slightly acidic and can be used in reel to reel lines and rack and barrel lines. The polyglycol ether can prevent discoloration during storage which causes problems in soldering, and it is relatively unaffected by temperature, so that no operation of the freezer is required during the summer, and the corrosion of tin and tin alloy is suppressed not only at room temperature but also at high temperature . In addition, it is in a liquid form which is easy to use and is more advantageous because it contains no complexing agent.

In the present invention, the antioxidant is used at a concentration ranging from 8% by volume to 13% by volume. When the concentration of the antioxidant is lower than 8 vol%, the effect of suppressing the generation of black dust is disadvantageously disadvantageous. When the concentration of the antioxidant is higher than 13 vol%, a defective gloss occurs during the reflow treatment.

According to the tin plating method of the present invention, the application of the antioxidant in the flux step is surprisingly made by the mist spraying method, unlike the conventional deposition method or the nozzle (spray) spraying method. When the application of the antioxidant in the flux stage is carried out by the conventional deposition or nozzle spraying method, the oxide film removing ability due to the aging of the antioxidant is lost and the aged antioxidant is applied to the tin plating surface, The reoxidation of the ash surface and the limitation of the spraying or deposition process itself cause exposure of the tin-plated surface to the air until it is introduced into the reflow step, causing problems such as oxide regeneration of the tin plating and, on the other hand, And the necessity of replacing caused a problem such as shutdown of the facility (facility incompatibility). However, since the mist system of the present invention is directly applied to reflow processing in a state where an antioxidant is sprayed on the surface of the workpiece, the exposure of the air is minimized in the process, the used antioxidant is not introduced into the chemical storage tank, As a result, the oxidation of the antioxidant itself can be prevented by preventing the entry of the oxide into the medicine.

In addition, when the immersion or nozzle spraying method is employed, the drug is not evenly applied to the surface of the raw material, and thus, a stain defect occurs after passing through the reflow step. On the other hand, the mist spraying method applied in the present invention causes the anti- To form an atmosphere of an antioxidant, thereby uniformly coating the surface of the tin-plated copper alloy material, which is a raw material, to prevent smearing.

In the mist spraying method, the antioxidant may be sprayed at a pressure of 1 to 2 kg / cm ² . When the mist spraying pressure is less than 1 kg / cm ² , the effect of suppressing black dust (smut) generation is insufficient due to a small supply amount of the chemicals. When the mist spraying pressure is more than 2 kg / cm ² , Is generated.

The mist spraying method of the present invention exhibits surprising and unpredictable improvements in terms of quality and efficiency, respectively, as described above. More specifically, since the mist spraying device is formed in an atmosphere of an antioxidant and is deposited on the surface of the plating material, it is possible to prevent the defective stain caused by the flow of the antioxidant drug in the conventional deposition and spraying method.

From the viewpoint of efficiency, it is possible to prevent the contamination due to the reuse of the chemical because the chemical mist is not reused in the mist spraying method, and the facility utilization ratio is improved by about 6% compared to the spraying method because no renewal facility is not caused due to the chemical contamination. In addition, since contamination of the water-cooled bath used in the reflow process, which is a post-process of the flux process, can be prevented, the equipment cost required for updating the water-cooling bath can be further prevented. In addition, the roll slip failure and the discoloration failure of the water-cooled tank are improved due to the mist system.

Next, in the tin plating method for a copper alloy material according to the present invention, the reflow step is a step of applying a gloss to the surface of the tin plating layer and preventing the formation of whiskers. The reflow step is performed at 500 to 600 DEG C for 1 to 5 minutes, Heating method. When the reflow processing temperature is lower than 500 ° C, matte defects or gloss defects occur. On the other hand, when the reflow processing temperature is higher than 600 ° C, blue plating due to heating may occur on the tin plating material side.

In the conventional method, when the spraying or deposition method is adopted in the flux step, which is the previous step, the oxide film on the surface of the tin plating formed by the aging or contamination of the antioxidant drug used in the previous step causes the tin plating layer A large amount of black dust is generated on the surface of the substrate. However, according to the present invention, since the antioxidant is applied in a mist spraying method in the flux step, an oxide film is not generated or hardly occurs on the tin plating surface, and the occurrence of smut during the reflow step can be drastically reduced.

The drying step is a step of removing moisture from the surface of the plated metal material by using an air blower heating system at 100 to 300 ° C for 1 to 5 minutes.

The tin plating method of the copper alloy material according to the present invention may further comprise an automatic inspection step after the drying step. The automatic inspecting step is a step of detecting with a camera such as a defective foreign matter on the surface of the tin plating material, bubbles, unevenness, and insect pressing.

Conventionally, a large amount of black powder (smut), which is an oxide, has been formed on the surface of the tin plating layer during the tin plating of the copper alloy mainly in the flux step, reflow step and / or drying step. When such a black powder is generated, as shown in FIG. 1, when a tin-plated copper alloy material is manufactured in a subsequent process, it can be seriously adversely affected by accumulation in a press or the like.

The black powder is composed mainly of tin oxide as tin oxide. These black powders are believed to be formed by heat being applied to the tin plated layer or by oxidation on the tin plated surface as exposed in air. There is a problem in that the generation of the black powder necessitates the maintenance of the facility downtime for the cleaning due to the contamination of the flux and the reflow water-cooling tank, and the workability is deteriorated due to contamination of the roll in the slitter process Occurs. In particular, it takes 12 hours or more every week to rinse the equipment for cleaning, which causes the productivity to decrease.

In the tin plating method of the copper alloy material of the present invention, as described above, the production of black powder which is tin oxide is suppressed, whereby a tin-plated copper alloy material of high quality can be manufactured and the problem of facility irreversibility and workability deterioration can be solved It has a remarkable improvement effect on the efficiency of the facility operation. The mist spraying method has not been used at all in the flux process in the tin plating method.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

Example

Example  One

The copper alloy material, which is the base material to be plated, was prepared by cutting the material to a width of 310 W and a length of 2,800 m or more at a wide range (over 600 width) The copper alloy material was electrolytically degreased by a cathodic electrolytic degreasing method, immersed in 10% sulfuric acid for 10 seconds, acid dipped and activated and pickled. Then, a copper sulfate copper content of 40 g / L and sulfuric acid of 110 g / L The copper alloy substrate was immersed in a copper plating solution for 4 minutes to be copper plated, and the copper plated copper alloy material was pre-dipped in 6 vol% of methane sulfonic acid (MSA) for 3 seconds.

Next, the obtained copper alloy material was immersed in a mixed solution of 28 vol.% MSA, 40 g / l of an organic acid, and 100 ml / L of an additive. The tin electrode for the positive electrode and the negative electrode were heated to 1,200 Lt; RTI ID = 0.0 > 30 C < / RTI > for 3 minutes using a rectifier device.

Then, 10% by volume of a polyglycol ether as an antioxidant was placed on both sides of the tin-plated copper alloy material located in a cell where a flux treatment was performed using air and an adiabatic nozzle, and 20 seconds Cm < ² > at a pressure of 1.5 kg / cm < ² > to form a mist atmosphere in the cell and flux treatment to the tin-plated copper alloy material.

Subsequently, the obtained copper alloy material was sintered at 550 DEG C for 2 minutes Lt; RTI ID = 0.0 > reflow < / RTI > Subsequently, the obtained copper alloy material was dried at 200 DEG C for 4 minutes. The final obtained sample was referred to as sample 1.

Comparative Example  One

Except that 10 vol% methanesulfonic acid (MSA) was used as an antioxidant used in the flux step and spraying method of the antioxidant was sprayed in the same manner as in Example 1, and tin-plated copper alloy A re-sample was obtained, which was referred to as sample 2.

Comparative Example  2

A tin-plated copper alloy re-sample was obtained in the same manner as in Example 1, except that the spraying method of the antioxidant (polyvinyl ether of 10 vol%) was used.

Comparative Example  3

A tin-plated copper alloy re-sample was obtained in the same manner as in Example 1, except that a dipping method was used for the application method of the antioxidant (10 vol% polyglycol ether) in the flux stage, to give Sample 4 .

Comparative Example  4

The copper alloy material was prepared in the same manner as the copper alloy material prepared in Example 1. In the same manner as in Example 1, except that the spraying method was used instead of the mist spraying method and the concentration gradient of the antioxidant polyglycol ether was 0.1 to 5% by volume in the flux step, tin plating . The obtained sample was referred to as sample 5.

Comparative Example  5

Except that the content of the polyglycol ether as the antioxidant was 8% by volume in spraying the mist in the flux step and directly applied on the tin-plated copper alloy material through air and air jet spraying, in the same manner as in Example 1 Prepared. The obtained sample was referred to as Sample 6.

Comparative Example  6

Except that 12% by volume of an antioxidant (polyglycol ether) was sprayed on the tin-plated copper alloy material through the air and the air jet during spraying the mist in the flux step, Respectively. The obtained sample was referred to as Sample 7.

Test Example  One

The tin-plated copper alloy re-samples 1 to 7 obtained according to the above-described Example 1 and Comparative Examples 1 to 6 were checked for gloss and occurrence of stains. The gloss and the degree of staining occurring on each tin-plated surface layer were compared, and the results are shown in Table 1 and Fig. 2 below.

sample Injection method stain Antioxidant Type and Content Gloss change Other One Example 1 mist Not occurring Polyglycol ether
10 vol% Improved gloss Install the barrier
(Preparation of antioxidant drug atmosphere) 2 Comparative Example 1 spray Occur Methanesulfonic acid (MSA)
10 vol% X - 3 Comparative Example 2 spray Occur Polyglycol ether
10 vol% X - 4 Comparative Example 3 deposition Occur Polyglycol ether
10 vol% X - 5 Comparative Example 4 spray Occur Polyglycol ether
Gradually increase by 0.1 to 5% by volume X - 6 Comparative Example 5 mist Somewhat Occurred Polyglycol ether
8 vol% Matte bad only on side Apply the medicine directly to the surface of the material 7 Comparative Example 6 mist Somewhat Occurred Polyglycol ether
12 vol% Matte bad only on side Apply the medicine directly to the surface of the material

FIG. 2 is a photograph for confirming whether or not a sample produced in accordance with Comparative Examples 1 to 6 and Example 1 was stained. It can be confirmed that only the sample prepared according to Example 1 does not cause staining.

As can be seen from Table 1 and FIG. 2, the spraying method and the dipping method cause unevenness on the surface of the tin-plated copper alloy material and low glossiness. However, when applied by the mist spraying method as in the present invention, It can be confirmed that the gloss is improved.

Example  2

A tin-plated copper alloy re-sample was obtained in the same manner as in Example 1, except that PMC26 was used as the copper alloy material. The obtained sample was referred to as Sample 8.

Comparative Example  7

PMC26 was used as the copper alloy, and 10 vol% of MSA as the antioxidant was flux-treated for 8 seconds at a temperature of 20 占 폚 in a spraying manner. The obtained sample was referred to as sample 9.

Test Example  2

The samples prepared according to Example 2 and Comparative Example 7 were each subjected to glossiness, solderability, amount of generated smur, salt water spray, heat peeling, and observation of plating texture.

Based on the results of the glossiness, the solderability was evaluated by a solderability measuring instrument (manufactured by RHESCA CO. LTD. (Japan), device name: SAT-5100) based on the glossiness of the glossiness meter (manufacturer: NIPPON DENSHOKU , And the amount of smut generated was compared based on digital microscopy. The salt spray was evaluated by comparing the degree of corrosion of the surface after 24 hours after spraying the surface of the solution at 35 DEG C composed of 95 vol% of water and 5 vol% of NaCl. The heat resistance peeling was evaluated by taper peeling test after annealing at 180 ° C for 1 hour, after bending at 90 °. Platelet morphology was evaluated with a 5000-fold SEM image.

Item Example 2
(Sample 8) Comparative Example 7
(Sample 9) result Antioxidant Polyglycol ester Methanesulfonic acid (MSA) Glossiness surface 151.6 128.6 30% higher than Comparative Example 7 Back 150.4 120.8 Solderability [t1-to] 0.72 sec 1.51 sec 50% reduction compared to Comparative Example 7 Amount of black dust (smut) generated 3 Comparative Example 7 Contrast reduction Salt spray See FIG. Good corrosion resistance Heat exfoliation 5 No peeling Plated tissue 6 Good (better organization is better)

As shown in Table 2 and FIGS. 3 to 6, in the case of the tin-plated copper alloy re-sample (sample 8 produced according to Example 2) produced according to the present invention, the existing tin- 3), the corrosion resistance is equally excellent (FIG. 4), the heat resistance peeling phenomenon does not occur (FIG. 5 (a) ) And a larger plating structure (Fig. 6).

Example  3

PMC26 (thickness: 0.2T) was prepared as a copper alloy material to be plated, and tin-plated in the same manner as in Example 1 above. The obtained sample was referred to as Sample 10.

Comparative Example  8

BA-H (thickness: 0.64T) was prepared as a copper alloy material to be plated. A tin-plated copper alloy re-sample was prepared in the same manner as in Comparative Example 1 to be referred to as Sample 11.

Reference example  One

JX A tin-plated copper alloy material produced by Ilkwang Iseok Metal Co., Ltd. was obtained and designated Sample 12. The copper alloy material used was B1 (thickness: 0.64 T).

Test Example  3

In this test example, the sample 10 of Example 3 prepared by the tin plating method according to the present invention, the sample 10 of the tin-plated Comparative Example 8 prepared by the existing tin plating method, and the reference of the tin-plated copper alloy material The degree of occurrence of black powder at the surface of the tin plating layer of Sample 11 of Example 1 was compared. The black powder generation test was carried out using a surface tester of JX Ilkwang Seisaku Metal Co., Ltd. (Tokyo, Japan) with a setting of 13 mm / s (gear box: 40 DS / min). The tin-plated surface was run in a friction manner twenty times.

Solderability of the samples was also measured according to the inspection standard, and the surface roughness was measured according to the inspection standard. The results obtained are shown in Table 3 and Figs. 7 to 8.

division Variety and specifications Solderability
(t1-to) The antioxidant used in the flux step Example 3
(Sample 10) PMC26 X 0.2T 1.01 sec Polyglycol ether Comparative Example 8
(Sample 11) BA-H X 0.64T 1.68 sec Methanesulfonic acid (MSA) Reference Example 1
(Sample 12) B1 X 0.64T 1.94 sec Methanesulfonic acid (MSA)

As a result of the test, as shown in Table 3 and FIG. 7, in the case of the tin-plated copper alloy material (sample 10) of Example 3 according to the present invention, the tin-plated copper alloy material of Comparative Example 8 (Sample 11), the solderability was improved, and the amount of black powder produced on the tin plating surface was remarkably reduced. 7 shows the ratio of the alloy layer of Cu and Sn, and the ratio of the Sn layer to the alloy layer is usually about 3: 7, which is stable to the reduction of the amount of black dust and the plating quality, And in the case of Reference Example 1, the ratio is about 3: 7.

8, in the case of the tin-plated copper alloy material (sample 10) of Example 3 according to the present invention, the solderability was improved as compared with the superior tin-plated copper alloy material (sample 12) It can be seen that the amount of the discharge is considerably reduced. That is, it can be confirmed that the tin-plated copper alloy re-sample 10 according to Example 3 is almost equivalent to the tin plating material of JX Sunlight Seesen Metal Co., Ltd., which is disclosed in Reference Example 1. [

The use of the tin plating method of the copper alloy material according to the present invention not only reduces the amount of black dust generated on the tin plating surface but also suppresses the occurrence of stains on the surface and improves the gloss have. This difference can lead to enormous efficiency differences in the tin plating method of copper alloy materials. That is, the tin plating method of the copper alloy material according to the present invention exhibits an excellent effect not only in suppressing the generation of black powder, improving gloss, reducing occurrence of stains, but also in productivity.

Claims (11)

As a tin plating method for a copper alloy material,
Electrolytically degreasing the tin-plated copper alloy material,
Pickling the electrolytically degreased copper alloy material,
The pickled copper alloy material is immersed in a copper plating solution Copper plating,
Pre-immersing the copper-plated copper alloy material in the preliminary immersion liquid,
Tin plating the pre-dipped copper alloy material,
Treating the tin-plated copper alloy material at 5 캜 to 30 캜 for 5 seconds to 10 seconds with an antioxidant,
Reflowing the obtained copper alloy material at 500 DEG C to 600 DEG C for 1 minute to 3 minutes, and
Drying the obtained copper alloy material at 100 DEG C to 300 DEG C for 1 minute to 5 minutes
Lt; / RTI >
Wherein the antioxidant is applied by a mist spraying method and the mist spraying is performed by forming an antioxidant atmosphere in a cell where flux is generated. The method according to claim 1,
Further comprising the step of automatically inspecting the dried copper alloy material after the drying step. The method according to claim 1,
Wherein the copper alloy material is selected from pure copper, brass, phosphor bronze, LF material, P-194, PMC26, or PMC102. The method according to claim 1,
Wherein the electrolytic degreasing is performed by a bipolar electrolytic degreasing method. The method according to claim 1,
Wherein the pickling step comprises an acid dip and an activation treatment method. The method according to claim 1,
Wherein the copper plating solution has a ratio of copper sulfate to sulfuric acid of 1: 1 to 1: 2. The method according to claim 1,
Wherein the antioxidant in said fluxing step is selected from phosphoric acid, sodium triphosphate, sulfurous acid, methanesulfonic acid, or polyglycol ethers. 8. The method of claim 7,
Wherein the antioxidant is a polyglycol ether. 8. The method of claim 7,
Wherein the concentration of the antioxidant ranges from 8 to 12% by volume. The method according to claim 1,
The mist jet is a copper alloy material is tin plating method is injected at a pressure of 1 to ² kg / cm 2 the antioxidant and the air through the fluid nozzle. delete

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