JP5151950B2 - Sn plating material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a Sn plating material which is a material for terminals and connectors used for a long time in a high temperature atmosphere of about 100 ° C. to 170 ° C., particularly in an engine room of an automobile, and a manufacturing method thereof.

  Conventionally, Cu or Cu alloy having excellent conductivity and mechanical strength is used as a base material as a material for various connectors and various terminals, and an Sn layer having good contact resistance and corrosion resistance is provided on this base material. Sn plating material is used.

  By the way, in the Sn plating material, the Sn layer is generally formed by an electroplating method. However, since the internal stress of the Sn layer is large, crystals grow in a bowl shape outward from the surface of the Sn layer, There has been a problem that whiskers that cause a short circuit accident occur.

  Therefore, it is known that the electrodeposited Sn layer is heated, and the reflow process of once melting and quenching is performed to release and remove the internal stress of the Sn layer to prevent the generation of whiskers.

  However, the Sn plating material subjected to the reflow treatment has whisker resistance and heat resistance, but is formed on the surface layer in a high temperature atmosphere of about 100 ° C. to 170 ° C. including in the engine room of a car. Since the thickness of the formed Sn is a thin film of 1 μm to 2 μm, the Cu component of the base material is thermally diffused at an early stage to form an intermetallic compound (Cu—Sn alloy) composed of Sn and Cu, and on the base material A Cu—Sn alloy layer is formed. As a result, since the surface layer of the Cu—Sn alloy layer is oxidized and hardened, there is a problem that the contact resistance with the counterpart material increases.

  On the other hand, Patent Document 1 proposes that an Sn layer or an Sn alloy layer and an Ag layer are sequentially formed on the surface of the substrate by electroplating. Further, Patent Document 2 proposes a method in which a Ni layer and an alloy layer of Ag and Sn (Ag—Sn alloy) layer are sequentially formed on the surface of the base material by electroplating. Further, Patent Document 3 proposes that an Sn layer or an Sn alloy layer and an Ag—Sn alloy layer are sequentially formed by electroplating. Even if these Sn plating materials are used for a long time in a high temperature atmosphere of 100 ° C. to 170 ° C., Ag is not diffused in the surface layer portion of the surface layer. Can be maintained.

JP 2002-317295 A JP 1999-350189 A Japanese Patent Laid-Open No. 2004-2225070

  However, in the invention described in Patent Document 1, when an Ag layer is formed by electroplating, a cyan plating solution is used as a plating solution. When this cyan is exposed to an acidic atmosphere, Since extremely toxic hydrogen cyanide gas is generated, it is impossible to mix acid / alkali wastewater and cyanate wastewater whose pH is not stable. Therefore, after plating, cyanide is oxidized to nitrogen and carbon dioxide. There was a problem that complicated treatment work such as decomposition and then merging with acid / alkaline waste water to remove metal ions was required.

  In the inventions described in Patent Document 2 and Patent Document 3, when an Ag—Sn alloy layer is formed by electroplating, the standard electrode potential of Ag (0.799 V) is Sn (−0.138 V). Therefore, in order to suppress the preferential precipitation of Ag, it is necessary to add a complexing agent to the plating solution. However, when adjusting the production amount of the Ag—Sn alloy within the specified range, it is necessary to control the composition and conditions of the plating solution, and there is a problem in the stability of the composition of the plating solution. There was a problem that it was difficult to continue forming the plating layer.

  Further, since the Ag layer or the Ag—Sn alloy layer formed by Patent Document 1, Patent Document 2, and Patent Document 3 is formed by electroplating, the Ag crystal structure is large and the Ag layer is formed thick. Tend to be. For this reason, although the contact resistance is good, there is a problem that the consumption of Ag forming the Ag layer is increased and the cost is increased.

  The present invention has been made to solve the problems of the prior art, and can be easily and reliably performed without using a cyan plating solution and without adjusting the plating solution with a complexing agent. An object of the present invention is to provide an Sn plating material capable of forming an Ag-Sn alloy layer and capable of reducing costs by forming the Ag layer into a thin film and a method for manufacturing the same. .

  In order to solve the above-mentioned problem, the method for producing a Sn-plated material according to claim 1 includes forming a Sn (tin) layer on the surface of a substrate made of Cu (copper) or a Cu alloy by electroplating. By applying a mixed solution of alcohol and water containing Ag (silver) nanoparticles on the Sn layer by a wet film formation method, the Ag nanoparticle coat layer is formed, and then subjected to a reflow treatment. An Ag—Sn alloy layer is formed on the surface of the Sn layer.

  The present invention according to claim 2 is characterized in that the Sn layer is formed on the surface of the base material after the Cu plating layer is formed by electroplating.

  Further, in the present invention described in claim 3, after forming a Ni (nickel) layer on the surface of the substrate by electroplating, the Cu plating layer is formed on the Ni layer, and then the Sn A layer is formed.

  Furthermore, the present invention according to claim 4 is characterized in that the particle diameter of the Ag nanoparticles is 5 nm or more and 100 nm or less.

  On the other hand, the present invention described in claim 5 is characterized in that the Sn plating material is manufactured by the method for manufacturing the Sn plating material according to any one of claims 1 to 4.

  According to the manufacturing method of Sn plating material of Claims 1-4, after forming Sn layer by the electroplating method on the surface of the base material which consists of Cu or Cu alloy, on this Sn layer, it is nano of Ag. Since the above-mentioned Ag nanoparticle coating layer is formed by applying a mixture of alcohol containing particles and water by a wet film forming method, it is a toxic cyan that is used when forming an Ag layer by electroplating. This eliminates the need to perform work such as removing metal ions by oxidizing cyanide and decomposing it into nitrogen and carbon dioxide gas, joining it with acid / alkali drainage after plating, .

  Also, by applying the reflow treatment, the surface layer of the Sn layer and the Ag nanoparticle coating layer are dissolved into an intermetallic compound, and an Ag3Sn layer that is an Ag-Sn alloy is formed on the Sn layer. Unlike the electroplating method, it is possible to easily and reliably form the Ag3Sn layer without requiring an operation such as adjusting the plating solution with a complexing agent. Moreover, this Ag3Sn layer has heat resistance and can maintain low contact resistance.

  By the way, normally, in order to maintain a low contact resistance, it is important to make the Sn plating layer thick and to increase the contact pressure for pressing the electrical contact portions such as indents and ribs. However, if the Sn plating layer is thickened and the contact pressure between the electrical contact portions is increased, when the terminal is inserted, deformation resistance increases due to the Sn plating being dug up, resulting in an increase in the insertion force of the terminal. When the insertion force is increased, the assembly work efficiency is reduced and the electrical connection is deteriorated due to poor bonding. Therefore, an Sn plating material having a low insertion force is required.

In this regard, according to the second aspect of the present invention, since the Sn layer is formed on the surface of the base material by electroplating and then the Sn layer is formed by reflow treatment, A thick Cu—Sn alloy layer is formed between the Sn layer. This Cu—Sn alloy layer is harder than Cu and Sn, and can exist as an underlayer for the Sn layer remaining on the outermost surface, thereby reducing the terminal insertion force.
Therefore, in actuality, since it can be easily inserted when used as a terminal and a connector, an Sn plating material capable of improving assembly work efficiency and suppressing deterioration of electrical connection due to poor bonding can be obtained. Can be manufactured.

  In addition, when the Sn plating material using Cu or a Cu alloy as the base material is used for a long time in a high temperature atmosphere, the lower layer of the Sn layer becomes a Cu—Sn alloy. Then, Cu of the Cu alloy diffuses, and a Kirkendall void is generated at the interface of the Cu-Sn alloy layer, the bonding strength between the Cu-Sn alloy layer and the base material is lowered, and the space is peeled off. There is a possibility that.

On the other hand, in particular, according to the present invention as set forth in claim 3, after the Ni layer is formed on the surface of the substrate by electroplating, the Cu layer is formed on the Ni layer, and then the above-mentioned Since the Sn layer is formed, even if Kirkendall voids are generated, the Ni layer ensures the adhesion between the Cu alloy and the Sn layer, so that the bonding strength increases, and the gap between them is peeled off. It is possible to prevent. The Ni layer also serves as a barrier layer for preventing Cu diffused from the base material.
Therefore, in actuality, when used as a terminal and a connector, it is possible to produce an Sn plating material in which the base material and the Sn layer do not peel even in a high temperature atmosphere of about 100 ° C. to 170 °.

  According to the present invention of claim 4, since the particle diameter of the Ag nanoparticles is 5 nm or more and 100 nm or less, it is extremely smaller than the crystal structure of Ag deposited by electroplating. . For this reason, compared with the conventional Ag layer, it is possible to form a thin Ag nanoparticle coat layer of Ag, so that it is possible to reduce the consumption of silver and to reduce the cost.

  Therefore, according to this invention of Claim 5, Sn plating material manufactured by these manufacturing methods maintains contact resistance with a counterpart material more reliably in a high temperature atmosphere of about 100 ° C to 170 ° C. In addition, it is possible to prevent the substrate and the Sn layer from peeling off.

(First embodiment)
First, a first embodiment of the Sn plating material according to the present invention will be described. As shown in FIG. 1 (b), this Sn plating material has a Cu 6 Sn 5 (ε phase) alloy layer 2 formed on the surface of a base material 1 made of a strip-like Cu—Zn alloy, and an Sn layer on the Cu 6 Sn 5 alloy layer 2. 3 is formed, and an Ag 3 Sn (ε phase) alloy layer 4 is formed on the Sn layer 3.

And compared with the Cu6Sn5 alloy layer 2 and the Sn layer 3, the thickness of the Ag3Sn alloy layer 4 is very thin.

  Next, the manufacturing method of 1st Embodiment of Sn plating material concerning this invention is demonstrated. First, as shown in FIG. 6A, the device 5 for forming the Sn plating material is arranged in the order of the tin plating tank 6, the die coater 7, and the reflow furnace 8 along the conveying direction of the substrate 1. The tin plating tank 6 stores stannous sulfate or tin methanesulfonate. The die coater 7 is a mixture of alcohol and water in which Ag nanoparticles are dispersed. The mixed solution of alcohol and water in which the Ag nanoparticles are dispersed uses ethanol or the like as the alcohol, and the Ag nanoparticles have a particle diameter of 20 nm. .

  In order to produce the Sn plating material by the apparatus 5 having the above-described configuration, first, in the tin plating tank 6, the base layer 1 is immersed in a stannous sulfate plating solution and an electric current is passed, whereby the Sn layer 3 is formed. Next, Ag nano-particle coating layer 9 is formed on Sn layer 3 by spraying Ag nanoparticles with die coater 7. Thereby, as shown to Fig.1 (a), the Sn layer 3 and the Ag nanoparticle coating layer 9 are formed in order on the base material 1. FIG.

  Next, the base material 1 on which the Sn layer 3 and the Ag nanoparticle coating layer 9 are formed is transported to the reflow furnace 8 and heated at 400 ° C. to 800 ° C. for about 0.5 seconds to 60 seconds. Thereby, the surface layer of the base material 1 which is a Cu—Zn alloy and the lower layer of the Sn layer 3 are dissolved into an intermetallic compound, and the Cu 6 Sn 5 alloy layer 2 is formed between the base material 1 and the Sn layer 3. The surface layer of the layer 3 and the Ag nanoparticle coat layer 4 are dissolved to form an intermetallic compound, and the Ag3Sn alloy layer 9 is formed on the Sn layer 3. Thereby, the Sn plating material of 1st Embodiment is obtained.

(Second embodiment)
Next, a second embodiment of the Sn plating material according to the present invention will be described.
In addition, about the structure same as 1st Embodiment, such as a structure of an alloy layer, description is abbreviate | omitted by using the same code | symbol.

  First, as shown in FIG. 2 (b), this Sn plating material has a Cu 6 Sn 5 alloy layer 2 formed on the surface of a substrate 1 made of a strip-like Cu—Zn alloy, and an Sn layer 3 on the Cu 6 Sn 5 alloy layer 2. The Ag3Sn alloy layer 4 is formed on the Sn layer 3.

  And compared with the Cu6Sn5 alloy layer 2 and the Sn layer 3, the thickness of the Ag3Sn alloy layer 4 is very thin.

  Next, the manufacturing method of the said Sn plating material is demonstrated. In addition, as shown in FIG.6 (b), the manufacturing method of this embodiment is the point which has provided the copper plating tank 10 which stored the copper sulfate plating solution in the upstream of the tin plating tank 6, and 1st Embodiment. Is different. Therefore, about the structure same as 1st Embodiment, such as the structure of the apparatus 5 which forms Sn plating material, description is abbreviate | omitted by using the same code | symbol.

  The manufacturing method of this embodiment forms the Cu layer 11 on the base material 1 by immersing the base material 1 in a copper sulfate plating solution and flowing an electric current in the copper plating tank 10, and then in the tin plating tank 6. The Sn layer 3 is formed on the Cu layer 11 by immersing it in a stannous sulfate plating solution, and then Ag nanoparticles are sprayed on the Sn layer 3 by the die coater 7. A nanoparticle coat layer 9 is formed. As a result, as shown in FIG. 2A, the Cu layer 11, the Sn layer 3, and the Ag nanoparticle coat layer 9 are sequentially formed on the substrate 1.

  Next, the base material 1 on which the Cu layer 11, the Sn layer 3, and the Ag nanoparticle coating layer 9 are formed is carried to the reflow furnace 8 and heated at 400 ° C. to 800 ° C. for about 0.5 seconds to 60 seconds. Thereby, the surface layer of the base material 1 which is a Cu—Zn alloy and the lower layer of the Sn layer 3 are dissolved into an intermetallic compound, and the Cu 6 Sn 5 alloy layer 2 is formed between the base material 1 and the Sn layer 3. The surface layer of the layer 3 and the Ag nanoparticle coat layer 9 are dissolved to form an intermetallic compound, and the Ag3Sn alloy layer 4 is formed on the Sn layer 3. Thereby, the Sn plating material of 2nd Embodiment is obtained.

(Third embodiment)
Next, a third embodiment of the Sn plating material according to the present invention will be described.
In addition, about the structure same as 1st Embodiment and 2nd Embodiment, such as a structure of an alloy layer, description is abbreviate | omitted by using the same code | symbol.

  First, as shown in FIG. 3 (b), this Sn plating material has a Ni layer 12 formed on the surface of a substrate 1 made of a strip-like Cu—Zn alloy, and a Cu 6 Sn 5 alloy layer 2 formed on the Ni layer 12. The Sn layer 3 is formed on the Cu 6 Sn 5 alloy layer 2, and the Ag 3 Sn alloy layer 4 is formed on the Sn layer 3.

  And compared with the Cu6Sn5 alloy layer 2, the Sn layer 3, and the Ni layer 12, the thickness of the Ag3Sn alloy layer 4 is very thin.

  Next, the manufacturing method of the said Sn plating material is demonstrated. In addition, as shown in FIG.6 (C), the manufacturing method of this embodiment is nickel plating which stored the watt bath which has nickel sulfate, nickel chloride, and boric acid as a main component on the upstream side of the tin plating tank 6. The point which has provided the tank 13 and the copper plating tank 10 which stored the copper sulfate plating solution in order is different from 1st Embodiment and 2nd Embodiment.

  The manufacturing method of this embodiment forms the Ni layer 12 on the base material 1 by immersing the base material 1 in a watt bath and flowing an electric current in the nickel plating tank 13, and then in the copper plating tank 10, A Cu layer 11 is formed on the Ni layer 12 by immersing it in a copper sulfate plating solution and flowing current, and then, in the tin plating tank 6, it is immersed in stannous sulfate plating solution and flowing current. An Sn layer 3 is formed on the layer 11. Next, Ag nano-particle coating layer 9 is formed on Sn layer 3 by spraying Ag nanoparticles with die coater 7. As a result, as shown in FIG. 3A, the Ni layer 12, the Cu layer 11, the Sn layer 3, and the Ag nanoparticle coat layer 9 are sequentially formed on the substrate 1.

  Next, the base material 1 on which the Ni layer 12, the Cu layer 11, the Sn layer 3, and the Ag nanoparticle coating layer 9 are formed is transported to the reflow furnace 8 at 400 ° C to 800 ° C for about 0.5 seconds to 60 seconds. Heat. As a result, the surface layer of the substrate 1 made of a Cu—Zn alloy and the lower layer of the Sn layer 3 are dissolved to form an intermetallic compound, and the Cu 6 Sn 5 alloy layer 2 is formed between the Ni layer 12 and the Sn layer 3. The surface layer of the layer 3 and the Ag nanoparticle coat layer 9 are dissolved to form an intermetallic compound, and the Ag3Sn alloy layer 4 is formed on the Sn layer 3. Thereby, the Sn plating material of 3rd Embodiment is obtained.

  According to the first to third embodiments of the manufacturing method of the Sn plating material described above, the Sn layer 3 is formed on the surface of the substrate 1 made of a Cu—Zn alloy by electroplating, and then the Sn layer 3 is formed. Since the Ag nanoparticle coating layer 9 is formed by applying a mixture of alcohol and water containing Ag nanoparticles on the top by die coating, the Ag layer is formed by electroplating as in the prior art. The toxic cyan plating solution used to form the metal is no longer used. After plating, cyan is oxidized and decomposed into nitrogen and carbon dioxide gas, combined with acid / alkali waste water, and metal ions. It is no longer necessary to perform operations such as removing the.

  Also, by applying the reflow treatment 8, the surface layer of the Sn layer 3 and the Ag nanoparticles become an intermetallic compound to form the Ag3Sn alloy layer 4, so that the plating solution is adjusted with a complexing agent as in the prior art. The Ag3Sn alloy layer 4 having heat resistance and capable of maintaining a low contact resistance can be formed easily and reliably without the need for such operations.

  On the other hand, since the particle size of Ag nanoparticles is 5 nm or more and 100 nm or less, it is extremely smaller than the crystal structure of Ag deposited by electroplating. For this reason, since it is possible to form the Ag nanoparticle coat layer 9 which is a thin film as compared with the conventional Ag layer, it is possible to reduce the consumption of silver and to reduce the cost. In addition, even if the Ag nanoparticle coat layer 9 is formed in a thin film, the Ag nanoparticle coat layer 9 and the surface layer of the Sn layer 3 are dissolved into the Ag3Sn alloy layer 4 by performing a reflow process. Contact resistance is not affected.

  Moreover, according to the Sn plating material of 1st Embodiment and its manufacturing method, after forming Sn layer 3 by the electroplating method on the surface of the base material which consists of Cu-Zn alloys, on this Sn layer 3, die-coater 7 to form an Ag nanoparticle coat layer 9 and then reflow treatment to form a Cu6Sn5 alloy layer 2 between the substrate 1 and the Sn layer 3, and an Ag3Sn alloy layer 4 on the Sn layer 3. As a result, the Cu6Sn5 alloy layer 2 becomes a barrier layer that prevents Cu diffused from the Cu-Zn alloy constituting the equipment 1, and the diffused Cu does not reach the outermost layer Ag3Sn. It is possible to prevent an increase in contact resistance of the Sn plating material.

Therefore, the first embodiment of the Sn tin plating material obtained by this manufacturing method is
Even if it is used for a long time in a high temperature atmosphere of about 170 ° C., it is possible to maintain the contact resistance with the counterpart material.

  Furthermore, according to the Sn plating material and the manufacturing method thereof of the second embodiment, the Cu layer 11 is formed on the surface of the substrate 1 made of the Cu—Zn alloy by electroplating, and the Sn layer 3 is formed on the Cu 11. Therefore, the thick Cu6Sn5 alloy layer 2 is formed between the base material 1 and the Sn layer 3 by the reflow process. The Cu6Sn5 alloy layer 2 is harder than Cu and Sn, and is present as an underlayer of the Sn layer 3 remaining on the outermost surface, so that the terminal insertion force can be reduced.

  Therefore, since the tin plating material obtained by this manufacturing method can be easily inserted when actually used as a terminal and a connector, the assembly work efficiency is improved, and electrical connection due to poor bonding is achieved. Deterioration can be suppressed.

  And according to the Sn plating material of 3rd Embodiment and its manufacturing method, after forming the Ni layer 12 by the electroplating method on the surface of the base material 1 which consists of a Cu-Zn alloy, on this Ni layer 12, Since the Cu layer 11 is formed and then the Sn layer 3 is formed on the Cu layer 11, the Ni layer 12 ensures adhesion between the base material 1 and the Sn layer 3 even if Kirkendall voids are generated. Therefore, it is possible to prevent the separation between the base material 1 and the Sn layer 3 by increasing the bonding strength. The Ni layer 12 also serves as a barrier layer that prevents Cu diffused from the base material 1.

  Therefore, the Sn plating material formed by this manufacturing method does not peel off the base material 1 and the Sn3 layer even when operated for a long time in a high temperature atmosphere of about 100 ° C. to 170 ° C. It is possible to maintain the contact resistance more reliably.

  The Sn layer 3 is formed on the base material 1 made of a Cu—Zn alloy by performing an electroplating method in the tin plating tank 6, and the silver coater is mixed with alcohol and water having a silver weight of 5 wt% on the Sn layer 3 by the die coater 7. The Ag nanoparticle coat layer 9 is formed by spraying the liquid, and then heated at 600 ° C. for 30 seconds by the reflow furnace 8, and the Cu 6 Sn 5 alloy layer 2, the Sn layer 3, and the Ag 3 Sn layer 4 are sequentially formed on the substrate 1. Using the formed Sn plating material, the contact resistance before and after high temperature exposure was measured three times.

  At this time, the Sn layer 3 was formed to a thickness of 1 μm, and the Ag nanoparticle coating layer 9 was formed to a thickness of 50 nm. The Ag nanoparticles in the Ag nanoparticle coat layer 9 were those having a particle diameter of 20 nm.

  Then, using an electrical contact simulator (Yamazaki Seiki Laboratories), the contact is brought into contact with the above-mentioned Sn plating material and is gradually slid, and a load is continuously applied from 0 gf to 50 gf and then from 50 gf to 0 gf. The contact resistance value corresponding to the load was measured. Moreover, in order to measure the contact resistance value after high-temperature exposure, the contact resistance value according to the load was measured using the Sn plated material heated at 175 ° C. for 120 hours.

  At this time, in order to compare the above Sn plating materials, the measurement conditions were the same under the same conditions using a conventional Sn plating material in which the Sn layer 3 was formed to a thickness of 1 μm on the substrate 1 made of a Cu—Zn alloy. The contact resistance was measured three times.

  FIG. 4A is a diagram showing changes in the contact resistance value according to the load applied to the Sn plating material of the prior art at normal temperature, and FIG. 4B is the Sn plating of the prior art after high temperature exposure. It is a figure which shows the change of the contact resistance value according to the load applied to the material. FIG. 5 (a) is a diagram showing a change in the contact resistance value according to the load applied to the Sn plating material at room temperature, and FIG. 5 (b) shows the Sn plating material after high temperature exposure. It is a figure which shows the change of the contact resistance value according to the applied load. In addition, the X-axis shows the load applied to the Sn plating material, and the Y-axis shows the contact resistance value corresponding to the load.

First, when comparing the Sn plating material of the prior art and the Sn plating material at room temperature,
As shown in FIG. 4A and FIG. 5A, it was confirmed that the contact resistance value could be maintained even when a load was applied to both.

  Here, in particular, when a contact resistance value of 25 gf (outward), which is the middle of the load applied to both Sn plating materials, is extracted, the Sn plating material of the prior art is 2.033 mΩ, and the Sn plating material is 1.400 mΩ. Both have low contact resistance values. At this time, since the contact resistance value of the Sn plating material was slightly lower, it was confirmed that the contact resistance could be maintained more than that of the conventional Sn plating material.

  On the other hand, when comparing the Sn plating material of the prior art after the high temperature exposure with the Sn plating material, the contact resistance value of the Sn plating material of the prior art is greatly increased as shown in FIG. I can confirm that. On the other hand, as shown in FIG.5 (b), it has confirmed that the contact resistance value of the said Sn plating material hardly changed with the normal temperature.

  Here, in particular, when the contact resistance value of 25 gf (outward), which is the middle of the load applied to both Sn plating materials, is extracted, the Sn plating material of the prior art is 13.04 mΩ, which greatly increases the contact resistance value. Oops. On the other hand, the Sn plating material was 2.497 mΩ, and it was confirmed that the contact resistance value could be maintained. Since this contact resistance value is a numerical value that is almost the same as the contact resistance value at normal temperature of the prior art, it was confirmed that the Sn plating material was very excellent in maintaining contact resistance. .

  From the above, the Sn plating material in which the Cu6Sn5 alloy layer 2, the Sn layer 3, and the Ag3Sn alloy layer 4 are sequentially formed on the base material 1 has sufficient heat resistance and maintains a low contact resistance value. It was proved that is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a first embodiment of a Sn plating material according to the present invention, where (a) is a cross-sectional view before reflow, and (b) is a cross-sectional view after reflow. The 2nd Embodiment of Sn plating material which concerns on this invention is shown, (a) is sectional drawing before reflow, (b) is sectional drawing after reflow. The 3rd Embodiment of Sn plating material which concerns on this invention is shown, (a) is sectional drawing before reflow, (b) is sectional drawing after reflow. The experimental result of a present Example is shown, (a) is a figure which shows the change of the contact resistance value according to the load applied to Sn plating material which formed Sn layer on the base material at the time of normal temperature, (b (A) is a figure which shows the change of the contact resistance value according to the load applied to the Sn plating material which formed Sn layer on the base material after high temperature exposure. The experimental result of a present Example is shown, (a) is according to the load applied to the Sn plating material which formed the Cu-Sn alloy layer, Sn layer, and Ag-Sn alloy layer in order on the base material at normal temperature. (B) is a load applied to a Sn plating material in which a Cu—Sn alloy layer, a Sn layer, and an Ag—Sn alloy layer are sequentially formed on a substrate after high temperature exposure. It is a figure which shows the change of the contact resistance value according to this. The apparatus which manufactures the Sn plating material in this invention is shown, (a) is explanatory drawing of the apparatus of 1st Embodiment, (b) is explanatory drawing of the apparatus of 2nd Embodiment, (c) These are explanatory drawings of the apparatus of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 3 Sn layer 4 Ag3Sn alloy layer (Ag-Sn alloy layer)
9 Ag nanoparticle coating layer 11 Cu layer 12 Ni layer

Claims (5)

  After forming a Sn layer on the surface of a substrate made of Cu or a Cu alloy by electroplating, a mixture of alcohol and water containing Ag nanoparticles is applied onto the Sn layer by a wet film formation method. A method for producing an Sn plating material, comprising: forming an Ag nanoparticle coat layer by Ag, and then performing a reflow treatment to form an alloy layer of Ag and Sn on the surface of the Sn plating layer.   The method for producing a Sn-plated material according to claim 1, wherein the Sn layer is formed on the Cu layer after forming a Cu layer on the surface of the substrate by electroplating.   3. The Sn layer according to claim 2, wherein a Ni layer is formed on the surface of the substrate by electroplating, and then the Cu layer is formed on the Ni layer, and then the Sn layer is formed. Manufacturing method of plating material.   The method for producing a Sn-plated material according to any one of claims 1 to 3, wherein a particle diameter of the Ag nanoparticles is 5 nm or more and 100 nm or less.   An Sn plated material produced by the method for producing an Sn plated material according to any one of claims 1 to 4.

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