JP2010280955A - Plated connecting terminal member, connecting terminal using the same, plated material and multilayer plated material used for the same and method of manufacturing plated connecting terminal member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting terminal member capable of suppressing or preventing the occurrence of whisker while suppressing the quantity of a rare metal to be used and improving both of solderability (wettability) to lead-free solder and slidability. <P>SOLUTION: The connecting terminal member is formed by reflowing a multilayer plated material having a first plating layer comprising tin or a tin alloy on the outside of the conductive base material and a second plating layer comprising indium on the first plating layer. The thickness of the first plating layer in a connection/disconnection part of the connecting terminal member is controlled to 0.3-3 μm, the thickness in the soldered part of the connecting terminal member is controlled to be thicker than that of the connection/disconnection part and the thickness of the second plating layer is controlled to 0.05-0.2 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a connection terminal member having a lead-free plating film, a connection terminal using the same, a plating film material and a multilayer plating material used therefor, and a method for manufacturing a plating film connection terminal member.

There are various types of connection terminals used for electrical connection, ranging from in-vehicle terminals to connector terminals (hereinafter referred to as PCB terminals) used for printed circuit boards. Required. FIG. 12 is a cross-sectional view schematically showing the PCB terminal. The PCB terminal 100 includes a male terminal 50 and a female terminal 60, and a male terminal member 51 and a female terminal member 61 are inserted into housings 55 and 65 of the respective terminals. When the female terminal 60 is moved in the direction of the arrow (S) as a whole and inserted into the receiving port 54 of the male terminal 55, the needle-shaped male member insertion / extraction portion 51a is inserted into the cylindrical female member. Connection state can be obtained.
The structure of the terminal member will be described in detail based on the male terminal member 51. The terminal member 51 has an insertion / extraction part 51a that fits with a mating female member on the TAB (Tape Automated Bonding) side, and a soldering part 51b that is soldered on the PCB side. . The soldering portion 51b is connected to the lead wire 52 and extends to the outside of the terminal through the portion fixed by the grip portion 53, and the lead wire is connected to the printed circuit board. As a terminal member of such a PCB terminal, one in which a copper alloy such as brass is used as a base material and a tin plating layer is formed on the surface is generally used. By applying tin plating in this way, on the mating side of the electrical contact portion, it is possible to provide a low contact resistance and good slidability, and further to impart corrosion resistance to the surface. On the other hand, good solderability can be realized at the soldering portion.

  In recent years, there has been an increasing demand for downsizing of the PCB terminal and high density of the number of connection terminal portions (pins), and as a countermeasure, it is required to reduce the insertion force when connecting. However, in the case of tin plating as described above, tin is a soft metal, so plastic deformation easily occurs at the time of insertion, and the deformed portion becomes resistance at the time of insertion, and a large insertion force is required for fitting. There is. Therefore, it is conceivable to reduce the thickness of the tin plating layer. However, this usually leads to a decrease in solderability.

  Further, the tin plating layer has a problem that whiskers are easily generated due to internal stress, diffusion of a base metal including a base, or the like. Once a whisker occurs and comes into electrical contact with another conductive member, etc., it may cause a short circuit and affect the operation of the device, as well as seriously affect electronic elements and semiconductors. It can be. As a countermeasure, it has been proposed to perform a reflow treatment after tin plating. Further, in the PCB terminal as described above, gold plating is used particularly for the fine pitch. Needless to say, it is desirable to reduce the amount of such expensive metals used as much as possible.

  By the way, in recent years, the composition of solder materials has changed significantly. Conventionally, 63Sn-37Pb (tin-lead) solder has been widely used, but due to environmental regulations such as the Waste Disposal Act, there is concern about the impact on the environment, such as lead being designated as a special management substance. The transition to lead-free solder (lead-free solder) is rapidly progressing. In order to cope with this, it is required to apply a lead-free material. In addition to the conflicting characteristics such as slidability and solderability as described above, whisker generation must be prevented, and the development of technology that satisfies these requirements becomes more difficult. ing.

  Patent document 1 discloses what tin-plated and indium-plated. As a result, the appearance and solderability are improved. Patent Document 2 discloses a silver electroplating layer of silver, bismuth, copper, indium, or zinc on a tin electroplating layer, thereby improving slidability, solderability, and corrosion resistance. It can be done.

Japanese Patent Laid-Open No. 11-279791 JP 2002-317295 A

  In order to achieve both the improvement in slidability and the improvement in solderability as described above, the present inventors vary the thickness of the tin plating layer between the insertion / extraction portion and the soldering portion in one terminal member. The use of differential thickness plating was studied. However, when using a combination of a tin layer and a metal material layer other than tin in order to achieve this in a lead-free plating layer, it is difficult to achieve both slidability and solderability of the difference thickness plating. It is believed that there is. In particular, when the reflow treatment is performed, it is considered that the plurality of metals are alloyed in the layer and a difference in the alloy composition is caused due to a difference in thickness depending on the location, and prediction and control of the characteristics become more difficult.

  Furthermore, the present inventors improve the fatigue durability of the solder joint when using the plating film connecting terminal member including the terminal member for PCB terminal for a long period of time as well as improving the above-mentioned characteristics. Focused on doing. As its background, for example, even if it is made as fine as a PCB terminal as well as an in-vehicle connection terminal, it has recently been incorporated into a complicated and advanced control system mounted on a moving means such as an automobile or a railway. . As a result, the connection terminals are miniaturized and refined, and the usage conditions are dynamic. Further, it cannot be said that fatigue durability is not necessary even for a large computer or a personal computer used statically. The inside of a computer, particularly the periphery of a built-in CPU (central processing unit), becomes considerably hot, and this increase in temperature during use and slow cooling when not in use are frequently repeated daily. Then, it is conceivable that the terminal joint portion repeatedly expands and contracts as the heat rises and falls, and gradually accumulates strain that causes cracks. Depending on the application, there is a need for a design with sufficient margin that does not cause such crack breakage when used for a long period of time.

  In view of the specific problems required for a plating film containing no lead as described above, the present invention suppresses the amount of rare metal used that is costly and also points to difficulty in obtaining the future, and solder for lead-free solder. It is an object of the present invention to provide a connection terminal member having a plating film that can improve both attachment properties (wetting properties) and slidability and can suppress or prevent the generation of whiskers. Another object of the present invention is to provide a plating film connection terminal member that reduces the soldering temperature with the above-mentioned good characteristics and has excellent fatigue durability, a connection terminal using the same, a plating film material used therefor, and a multilayer plating material. Furthermore, it aims at providing the manufacturing method of the plating film connection terminal member especially suitable for the manufacture.

The above problems have been solved by the following means.
(1) A connection terminal obtained by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer A member,
For the first plating layer, the thickness at the insertion / extraction part of the connection terminal member is 0.3 to 3 μm, and the thickness at the soldering part of the connection terminal member is thicker than the thickness of the insertion / extraction part,
A plating film connection terminal member, wherein the thickness of the second plating layer is 0.05 to 0.2 μm.
(2) The connection terminal according to (1), wherein the concentration of indium in the second plating layer is decreased in an inclined manner from the plating surface side to the conductive substrate side by the reflow treatment. Element.
(3) The connection terminal member according to (1) or (2), wherein a base plating layer made of nickel or a nickel alloy is interposed between the first plating layer and the conductive substrate.
(4) The connection terminal according to any one of (1) to (3), wherein a base plating layer made of copper or a copper alloy is interposed between the first plating layer and the conductive base material. Element.
(5) The connection terminal member according to any one of (1) to (4), wherein the thickness of the second plating layer is uniform in the insertion / extraction portion and the soldering portion.
(6) The first plating layer is made of at least one selected from the group consisting of tin, tin-silver alloy, tin-bismuth alloy, tin-copper alloy, and tin-silver-copper alloy ( The connection terminal member according to any one of 1) to (5).
(7) The connection terminal member according to any one of (1) to (6), wherein a thickness of the insertion / extraction portion of the first plating layer is 1.5 μm or more.
(8) The difference (Td = Th−Ts) between the thickness (Ts) of the insertion / extraction portion of the first plating layer and the thickness (Th) of the soldering portion is set to 1.0 to 2.7 μm. The connection terminal member according to any one of (1) to (7).
(9) A connection terminal comprising the connection terminal member according to any one of (1) to (8).
(10) A plating film obtained by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer. It is a material, Comprising: The thickness of the said 1st plating layer shall be 0.3-3 micrometers, and the thickness of the 2nd plating layer shall be 0.05-0.2 micrometers, The plating film material for connecting terminals characterized by the above-mentioned.
(11) The plating film material according to (10), wherein the first plating layer is provided with a predetermined thickness portion and a thinner portion.
(12) A multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate, and a second plating layer made of indium on the surface of the first plating layer, the first plating layer A multilayer plating material for connection terminals, wherein the plating layer has a thickness of 0.3 to 3 μm and the second plating layer has a thickness of 0.05 to 0.2 μm and is reflowed.
(13) The multilayer plating material according to (12), wherein the first plating layer is provided with a portion having a predetermined thickness and a portion thinner than the predetermined thickness. Forming a first plating layer made of tin or a tin alloy, forming a second plating layer made of indium on the surface of the first plating layer to obtain a multilayer plating material for a connection terminal member, and reflowing the multilayer plating material; In making a connection terminal member having an insertion / extraction part and a soldering part,
About the said 1st plating layer, the thickness in the said insertion / extraction part shall be 0.3-3 micrometers, and the thickness in the said soldering part is made thicker than the thickness of the said insertion / extraction part, On the other hand, the thickness of the said 2nd plating layer 0.05 to 0.2 μm is used for the multilayer plating material, and the multilayer plating material is reflowed to form a connection terminal member.

The plated film connecting terminal member of the present invention solves the specific problems required for a terminal member having a plated film that does not contain lead, and suppresses the use of rare metals, which are expensive and point out that future availability is pointed out. On the other hand, in addition to improving solderability (wetting properties) and slidability (insertion / removability) with respect to lead-free solder, it has an excellent effect of suppressing and preventing whisker generation and growth. Moreover, the plating film connection terminal member of this invention implement | achieves reduction of the soldering temperature calculated | required in a terminal member with the said favorable characteristic, and also shows high fatigue durability.
The plating film material and the multilayer plating material of the present invention are particularly suitable as a material for the terminal member described above, and the terminal member using the same has high durability that does not cause breakage of the solder joint portion even when used for a long time as well as stable conduction. And the reliability of the equipment based on it.
Moreover, according to the manufacturing method of this invention, the plating film connection terminal which has the above-mentioned favorable characteristic can be manufactured.

It is sectional drawing which shows typically the surface of the one part about one Embodiment of the plating film connection terminal member which comprises the plating film connection terminal of this invention, Fig.1 (a) is before reflow and FIG.1 (b) is reflow. Shown later. It is the side view (FIG. 2a) which shows typically one Embodiment of the plating film connection terminal member of this invention, and the graph (FIG. 2b) which shows the thickness of the plating film before the reflow. It is a graph which shows the result of the Auger analysis which shows the gradient distribution of tin and indium of the plating film material (test body) obtained by the manufacture example. It is a graph which shows the result of the Auger analysis which shows gradient concentration distribution of the tin and indium of another plating film material (test body) obtained by the manufacture example. It is a graph which shows the result of the solder wettability test of the test body obtained by the manufacture example. It is a graph which shows the result of the Bowden test of the test body obtained by the manufacture example. It is the microscope picture (drawing substitute photograph) which image | photographed the surface state of the test body obtained by the preparation example (magnification: 100 times). It is the microscope picture (drawing substitute photograph) which image | photographed the surface state of another test body obtained in the manufacture example (magnification: 100 times). 10 is a photomicrograph (drawing substitute photo) showing an enlarged surface state of the specimen [Sn 1.5 μm / In 0.2 μm] (2000h) shown in FIG. 9. FIG. 10 is a photomicrograph (drawing substitute photo) taken by enlarging the surface state of the specimen [semi-gloss Sn (1.5 μm)] (2000 h) shown in FIG. 9. It is a perspective view for demonstrating schematically the method of the fatigue life evaluation test of a plating film material (test body). It is a partial sectional view showing typically the general structure of a PCB terminal.

  There are no particular limitations on the material and shape of the conductive substrate that can be used for the plating film connection terminal of the present invention, and materials and shapes that are used in ordinary semiconductor devices can be used. Specifically, it is sufficient that at least the surface of the material has conductivity. Examples thereof include copper, iron, nickel, aluminum, and a base material formed by a combination thereof. It can be selected appropriately according to the purpose and application, and considering the use as a connection terminal, at least the surface constituent material is preferably a simple copper, copper alloy, stainless steel, iron-based alloy or the like. The shape of the conductive substrate is not particularly limited, but considering the use as a connection terminal, the shape of the conductive substrate is preferably a flat strip or a pressed strip.

  In the present invention, the first plating layer is made of tin or a tin alloy, and preferably tin (Sn), tin (Sn) -silver (Ag) alloy, tin (Sn) -bismuth (Bi) alloy, tin (Sn)- It consists of at least 1 sort (s) chosen from the group of a copper (Cu) alloy and a tin (Sn) -silver (Ag) -copper (Cu) alloy. Here, the melting point of each metal or alloy is as follows, and the material to be applied may be selected in relation to the reflow processing temperature described later and the melting point of indium. Especially, the material which comprises a 1st plating layer has preferable tin, a tin-silver alloy, a tin-bismuth alloy, or a tin-silver-copper alloy, and a tin or tin-silver alloy is more preferable. The melting point of the simple substance of tin is 231.9 ° C, the tin-3 mass% silver alloy is 220 ° C, the tin-5 mass% bismuth alloy is 227 ° C, the tin-0.7 mass% copper alloy is 227 ° C, the tin-3 mass% The melting point of the silver-0.5 mass% copper alloy is 219 ° C. In the case of a tin-silver alloy, the upper limit of the silver content is preferably 4% by mass. In the case of a tin-bismuth alloy, the upper limit of the bismuth content is preferably 5% by mass. In the case of a tin-copper alloy, the upper limit of the copper content is preferably 1% by mass. In these alloys, it is preferable that the content is within the above-described upper limit range because crack suppression and solder wettability are enhanced. In addition, indium constituting the second plating layer has a low melting point (156 ° C.), and in order to finely control the film thickness, a range in which the influence of the variation in the material and thickness of the first plating layer can be canceled out. It is preferable to select and adjust appropriately.

  In the present invention, the thickness of the first plating layer is 0.3 to 3 μm, and can be appropriately selected depending on the purpose of use and application within the range. When insertability is taken into account when used for a terminal member, the thickness of the first plating layer is preferably 0.5 to 1.5 μm, and more preferably 0.5 to 1.0 μm. Furthermore, considering the solderability when the connection terminal member is formed, the thickness of the soldered portion is preferably 1.5 to 3.0 μm, and more preferably 2.0 to 3.0 μm. . The difference (thickness difference Td = Th−Ts) between the thickness (Ts) of the first plating layer of the insertion / extraction portion and the thickness (Th) of the soldering portion may be set as appropriate according to the application, required performance, etc. 1.0 to 2.7 μm is preferable. By providing a difference in the thickness of the first plating layer between the insertion / extraction portion and the soldering portion as described above, it is possible to achieve both slidability (insertion / extraction properties) and solderability.

  In the plating film material of the present invention, indium is used for the second plating layer. The thickness of the second plating layer is 0.05 to 0.2 μm, and can be appropriately selected according to the purpose of use. In consideration of solderability and slidability when connecting terminal members, whisker suppression and fatigue resistance, the thickness is preferably 0.05 to 0.1 μm. By making the thickness of the indium plating layer equal to or higher than the above lower limit value, the occurrence of whiskers is remarkably suppressed, high fatigue durability is expressed, and by setting the thickness below the upper limit value, heat resistance is improved, for example, during reflow The fine unevenness | corrugation of the plating surface which arises can also be prevented suitably. Furthermore, in combination with the amount of indium, which is a metal having relatively low hardness, being suppressed to a small amount within the above range, good slidability (insertion / removability) can be realized. Further, it is preferable that the fatigue life can be maximized rather than increasing the thickness of the indium layer beyond this.

  In the present invention, as described above, the thickness of the indium on the plating surface layer side and the tin or tin alloy on the base layer side is defined in the above range, so that Sn-3Ag— which is a typical lead-free solder. When bonded to 0.5 Cu solder, solid-liquid diffusion occurs and solder wettability is enhanced. In addition, since indium on the surface layer side is a low melting point metal, it is possible to reduce the soldering temperature when mounting in combination with this point. Furthermore, according to the present invention, the indium of the second plating layer (surface layer) is suppressed to a thin thickness of 0.05 to 0.2 μm, and the desired effect is obtained by combining with the tin of the first plating layer or an alloy thereof. Therefore, there is an advantage not only in terms of cost but also from the viewpoint of resource saving that the amount of rare metal indium used can be suppressed to a small extent.

In the present invention, in addition to the above-described advantages, the indium layer constituting the second plating layer is further thinned, and a reflow treatment is performed to obtain an inclined concentration distribution, thereby providing a specific action.
First, the effect | action which suppresses generation | occurrence | production of a whisker is mentioned. In this way, if the interaction due to the presence of the metal in both layers in a gradient with a gradient is included, it can be explained as follows. In other words, by reflowing the tin or tin alloy layer laid at the specific thickness and the indium layer on the surface layer side, the indium on the surface phase side is appropriately diffused on the base metal side and arranged in an inclined manner, It is considered that moderate creep property of indium is obtained, and whisker generation / growth is suppressed. That is, the internal stress in the tin or tin alloy layer is relaxed, and as a result, the generation of whiskers is effectively suppressed.

  Furthermore, in the present invention, by defining the thickness of the indium layer so as not to exceed the above specific range with respect to the tin or tin alloy layer as described above, the fatigue of what was soldered instead when reflowed Durability can be increased. Therefore, extremely high reliability can be realized even when applied to a field or application where an accidental stop or the like is not permitted when, for example, a PCB terminal or a vehicle-mounted terminal is used. Furthermore, even a large-sized computer or the like having a large increase / decrease in internal temperature can suitably cope with long-term continuous use. In particular, Sn-3Ag-0.5Cu, which is currently the mainstream solder, has a concern that cracks are likely to occur and the fatigue life is shortened as compared with the conventional Sn-37Pb solder. However, according to the present invention, such a point becomes apparent. It is also possible to cope with a suitable application. Although there is still an unclear point about the mechanism of action to obtain such an effect, the stress relaxation effect in the plating film resulting from the two types of metals described above being inclined is involved. Conceivable.

  By the way, the soldering temperature in the connection terminal and the like has shifted from 220 ° C. where Sn-37Pb which is lead-containing solder is used to 240 ° C. or higher of Sn-3Ag-0.5Cu of lead-free solder. It has risen a lot. On the other hand, according to this invention, the solder wettability of a terminal member can be improved and it can make it easy to get wet at lower temperature. Therefore, the soldering temperature in the manufacturing process of various terminal members can be lowered, leading to significant energy reduction and improved reliability.

It is preferable to adjust the relationship between the thickness of the first plating layer and the thickness of the second plating layer before reflow as the heat treatment for the connection terminal member as follows. That is, it is preferable to consider the ratio (t ₂ / t ₁ ) between the thickness (t ₁ ) of the first plating layer and the thickness (t ₂ ) of the second plating layer. The ratio of the thickness of the first plating layer to the thickness of the second plating layer (t ₂ / t ₁ ) is preferably in the range of 0.02 to 0.04. By making this ratio (t ₂ / t ₁ ) equal to or less than the above upper limit value, the whisker suppression / prevention effect can be expressed more suitably. Appearance can be improved.

FIG. 1 is a cross-sectional view schematically showing the vicinity of a part of the surface of an embodiment of a plated film material constituting the plated film connection terminal member of the present invention. FIG. b) shows the state after reflow. Before the reflow, the first plating layer (tin or tin alloy) 1a and the second plating layer (indium) are arranged in this order on the surface of the conductive substrate 4, and each of the specific layer thicknesses d ₁ described above. And d ₂ by electroplating. Thereby, the multilayer plating film 3a is constituted. By reflowing the multilayer plating material 10a, the second plating layer 2a made of indium having a particularly low melting point melts and flows, and indium diffuses into the first plating layer made of tin or a tin alloy. The result of this diffusion, the concentration of indium toward the substrate 4 from the plating layer surface height - would exhibit low continuous gradient layer d _3. That is, the plating film layer 3 after reflow is not inclined or has a slightly inclined concentration distribution plating outer layer (mainly tin, tin alloy) 1 and a plated inner layer (indium-tin or tin) having an inclined concentration distribution. Alloy) 2.

Although indium is not particularly limited thickness of the graded layer d ₃ arranged at the concentrations inclined, total thickness of the first plating layer and the second plated layer before the reflow of _(d 1 ₊ d ₂₎ 1~10 % Is preferable, and 1 to 5% is more preferable. In terms specific thickness, when considering the use of a connection terminal, it is preferable that the inclined layer _{d 3} is 0.1 to 0.5 [mu] m, and more preferably 0.1~0.2μm . In addition, although it is not the differential thickness plating in the part shown in FIG. 1, when it is set to the differential thickness plating, it is the same that the arrangement of the metal material is inclined after the reflow. At this time, since the difference thickness plating within the thickness range of the first plating layer defined in the present invention and the thickness of the second plating layer defined in the present invention, for example, in the insertion / extraction portion and the soldering portion, This is preferable because a desired effect can be obtained without requiring a detour treatment such as changing the thickness of the second plating layer.

  The reflow conditions as the heat treatment for the connection terminal member may be set in consideration of the substrate and the thickness of the plating. According to the present invention, reflow and heat treatment in soldering may be performed as the heat treatment, and this heat treatment temperature can be reduced. Speaking of the atmosphere temperature in the furnace when reflowing as the heat treatment, it is preferably set to 300 to 600 ° C. The time for the reflow treatment is preferably 1 to 10 seconds, and more preferably 2 to 5 seconds. It is preferable that the reflow treatment temperature is equal to or higher than the lower limit value in that the indium diffusion is sufficiently advanced and a desired tilt state is obtained. When the reflow temperature is not more than the above upper limit value, the indium gradient does not proceed more than necessary, and for example, whisker suppression can be sufficiently exerted, and the quality of electronic components and the like can be maintained.

  In the plating film material of the present invention, it is preferable to dispose an underlayer in advance on the surface of the conductive substrate prior to plating of tin or tin alloy. Examples of the underlayer include forming a layer made of nickel or a nickel alloy by electroplating. These base plating layers effectively function as a barrier for suppressing thermal diffusion of copper or the like of the conductive base material, and can improve the heat resistance of the plating layer having a two-layer structure formed thereon. In addition, it is preferable to apply a nickel alloy as the base plating because the diffusion of copper into the plating layer during reflow can be suppressed or prevented. Furthermore, it is preferable that the surface of the conductive substrate is preliminarily plated with copper or a copper alloy so that better conductivity can be imparted. On the other hand, another layer or the like may be provided outside the second plating layer.

  When a preferred embodiment of the production method of the present invention is given, the following steps (1) to (9) may be appropriately combined, and it is preferable to sequentially carry out these steps in that order. (1) Step of immersing and degreasing the conductive substrate and washing with water if necessary, (2) Step of electrolytic degreasing and washing with water if necessary, (3) Step of acid washing and washing with water if necessary, (4) Nickel plating (electroplating) (5) A step of applying tin plating (electroplating) and a step of washing with water if necessary, (6) A step of applying indium plating (electroplating) and a step of washing with water if necessary, (7) A drying step, (8 ) A step of performing reflow treatment as a heat treatment on the multilayer plating material, and (9) a step of soldering lead wires or the like to the male terminal or the female terminal.

In the step (1) of immersion degreasing, a commercially available immersion degreasing solution can be performed at a temperature of 50 ° C. for about 20 seconds within a concentration range of 2 to 4%. But the step of electrolytic degreasing (2), each commercially available electrolytic degreasing solution at about 5% concentration, current density 2~4A / dm 2 at about room ^temperature, can be performed in about 20 seconds. The acid washing step (3) is preferably performed at a concentration of 5% sulfuric acid and at room temperature for 20 seconds. The nickel plating step (4) can be performed using a nickel sulfamate bath at about 55 ° C. and a current density of 5 A / dm ² for 30 seconds. The tin plating step (5) can be performed using an acidic tin plating bath at about 30 ° C. and a current density of 5 A / dm ² for 40 seconds. The indium plating step (6) can be performed using a plating bath at about 30 ° C. and a current density of 0.5 A / dm ² for 120 seconds. In this way, the current density and the plating treatment time in the plating process can be set as appropriate, and the thicknesses of the first plating layer (tin, tin alloy) and the second plating layer (indium) can be set to the above specific ones. .

  Fig.2 (a) is a side view which shows typically one Embodiment of the plating film connection terminal member of this invention, FIG.2 (b) is the plating film layer (1st plating layer and 2nd plating before reflow). It is a graph which shows the thickness of a layer. The plated film connecting terminal member (male terminal member) 71 shown in the figure is the same type as the male terminal member 51 shown in FIG. 12, but is shown as having a slightly different shape. The male terminal member 71 has a needle-like insertion / extraction portion 71a on the TAB side, and is inserted and connected to a female terminal member (not shown). On the other hand, the other side of the printed circuit board is similarly shaped like a needle but is a soldered portion 71b that is soldered and connected to the lead wire. As shown in FIG. 2B, the first plating layer of the multilayer plating material that forms the connection terminal 71 before reflowing has a thickness of about 1.2 μm between the insertion / extraction portions I to III. On the other hand, the first plating layer is thickened to 3 μm between the soldering portions IV-V. The second plating layer is disposed with a uniform thickness of 0.2 μm as a whole. As described above, the connection terminal member 71 of the present embodiment is applied with the differential thickness plating so that the thickness of the first plating layer is increased from the insertion / extraction part to the soldering part, and a part having a predetermined thickness and a part having a thinner thickness than that are provided. And are provided. In this way, it can satisfy a plurality of required characteristics that have been difficult to realize at the same time, that is, it can satisfy both good insertion / removability and solderability, suppress whisker generation, and fatigue. By extending the service life, the durability and reliability of the device can be greatly increased.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is limited to this and is not interpreted.
(Production example)
Specimen 1
On a conductive substrate made of brass (35/65 brass) of 0.64 mm (thickness) × 20 mm (width), a base plating made of nickel was provided with a thickness of 0.5 μm. Thereafter, a tin plating layer of 1.5 μm was applied to the surface of the base plating, and an indium plating layer of 0.05 μm was formed on the surface of the tin plating layer to obtain a multilayer plating material. The multilayer plating material was subjected to a reflow treatment under an atmosphere temperature of 400 to 450 ° C. to obtain a test body 1 of a plating film material. This specimen 1 was subjected to Auger analysis in which the composition of tin and indium was measured by etching from the indium surface side to the base material side. As a result, it was confirmed that indium was present at a high concentration on the surface side, and the concentration decreased as it proceeded to the substrate side (see FIG. 3). The thickness of the graded layer d ₃ of indium is inclined arranged was estimated to be 0.1 [mu] m.

Specimens 2-10, c1-c8
A plated coating material was produced in the same manner as in the above test sample 1 except that the copper alloy (conductive substrate), the base plating, the first plating layer, and the second plating layer were changed as shown in Table 1. The specimen 10 was subjected to Auger analysis in the same manner as described above. As a result, it was confirmed that indium was present at a high concentration on the surface side, and the concentration decreased as it proceeded to the substrate side (see FIG. 4). The thickness of the graded layer _{d 3} of indium is inclined arranged was estimated to be 0.1 to 0.2 [mu] m.

(Examples and comparative examples)
Specimens 11-14, c9
A conductive substrate made of brass (35/65 brass) having a thickness of 0.64 mm (thickness) × 20 mm (width) is punched into the shape shown in FIG. 2A, and then a base plating made of nickel is formed to a thickness of 0.5 μm. It was provided. Thereafter, a tin plating layer of 1.0 μm is applied to the surface of the base plating, a tin plating layer of 3.0 μm is applied to the soldering portion, and an indium plating layer of 0.2 μm is formed on the surface of the tin plating layer. A plating material was obtained. The multilayer plating material was subjected to a reflow process under the conditions of an atmospheric temperature of 400 to 450 ° C. to obtain a test body 11 of a plating film material.
For the specimen c9, after obtaining the same multilayer plating material as that of the specimen 11, the reflow treatment was not performed. Test bodies 12 to 14 were obtained in the same manner as the test body 11 except that the plating thickness was changed.

<Solder wettability test>
Solder wettability was performed in accordance with JIS C0053 environmental test method-electrical / electronic-soldering test method (equilibrium method). To the molten solder (Senju Metal Industry Co., Ltd., Sn-3Ag-0.5Cu, Flux Mildrozin NA200 [trade name]), the specimen 1 (Sn1.5 / In0.05) obtained above and the specimen c1 ( Reflow Sn1.5) and specimen c2 (semi-gloss Sn1.5) were immersed for 2 seconds at solder temperatures of 230, 240, and 245 ° C., respectively, and the wettability of the solder was measured as a zero-crossing time. The zero crossing time is the time from when the solder begins to get wet until the acting force becomes zero, and the shorter the time, the easier the solder gets wet on the plating surface. The results are shown in FIG. Only the soldering part was tested for the test bodies 12-14 and c9.

<Frictional property test>
The test specimen 1 (Sn1.5 / In0.05) and the test specimen c1 (reflow Sn1.5) were subjected to a friction characteristic test as follows. Using a Bowden-type abrasion tester, the test was started at a load of 300 g and a sliding speed of 100 mm / min, and the dynamic friction coefficient was measured when the sliding distance was 10 mm and the sliding was performed 20 times. The results are shown in FIG. Regarding the dynamic friction coefficient obtained in the friction characteristic test, the test body 1 is equal to or less than or equal to the test body c1, and the practically required level is sufficiently satisfied with the currently used test body c1. It can be seen that the specimen 1 exhibits good performance in this characteristic. In addition, about the result of this test shown in Table 2, the test bodies 12-14 and c9 tested only the insertion / extraction part.

<Solder joint fatigue test>
As shown in FIG. 11, the test specimens 10 each having the plating film (the first plating layer and the second plating layer which have been reflowed and in an inclined state) 3 are plated on the conductive base material (brass) 4. The layers 3 were overlapped so as to face each other, and Sn-3Ag-0.5Cu solder applied to a thickness of 50 to 100 μm was interposed therebetween, and soldering was performed at 245 ° C. A test body was prepared in the same manner as the test body 1 except that the thickness of the indium layer was changed, and this was used as a test material for a solder joint fatigue test to measure a low cycle fatigue life. At this time, the conditions of strain 1%, speed 5 μm / sec, and 500 cycles were added in the length direction (amplitude direction in the figure) at the end of one of the test materials, and the state of the joint portion was visually or enlargedly observed. Relative evaluation.

<Whisker sensitivity test>
The specimen 3 (Sn 2 μm / In 0.05 μm) and the specimen c4 (semi-gloss Sn 2 μm) were allowed to stand at room temperature (about 28 ° C.) for 500, 1000, 2000, and 4000 hours and then observed by SEM to examine the state of the plating surface. . The results are shown in FIG. Similarly, the results (2000 h) of SEM observation of the specimens 1 and c3 are shown in FIGS.

[Evaluation criteria in each test]
・ Solder wettability (245 ℃)
◎ ・ ・ ・ Zero cross time is less than 1.0 seconds △ ・ ・ ・ Zero cross time is 1.0 seconds or more and less than 2 seconds × ・ ・ ・ Zero cross time is 2 seconds or more ・ Whisker sensitivity test (2000h)
◎ ・ ・ ・ No whisker generation △ ・ ・ ・ Slight whisker generation ×× Whisker generation

・ Frictional property test
◎ ・ ・ ・ Dynamic friction coefficient is equal to or smaller than specimen c1 ○ ・ ・ ・ Dynamic friction coefficient is slightly larger than specimen c1 × ・ ・ ・ Dynamic friction coefficient is larger than specimen c1 ・ Solder joint Fatigue test ◎ ・ ・ ・ No or almost no crack ○ ○ Slightly cracked − ・ ・ ・ Not tested

  As can be seen from the above results, the plating film material to which the first plating layer and the second plating layer having a thickness applied to the plating film connection terminal of the present invention are applied is a gradient of indium and tin by reflow treatment. It can be seen that the concentration distribution is realized, good solder wettability and slidability, whisker prevention, and high fatigue resistance (cracking suppression) are realized.

1 Plating inner layer (region on the first plating layer side after reflow)
1a First plating layer 2 Plating outer layer (region on the second plating layer side after reflow)
DESCRIPTION OF SYMBOLS 1a 2nd plating layer 3 Plating film layer after reflow 3a Multilayer plating film 4 Conductive base material 10 Plating film material (connection terminal member)
10a Multilayer plating material (precursor of connection terminal member)
50 Male terminal 51, 71 Male terminal member 51a, 71a Insertion / extraction part 51b, 71b Soldering part 52 Lead wire 53 Grip part 54 Male terminal receptacle 55 Male terminal housing 60 Female terminal 61 Female terminal member 65 Female terminal housing 100 Terminal (connector)

The above problems have been solved by the following means.
(1) A connection terminal obtained by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer A member,
For the first plating layer, the thickness at the insertion / extraction part of the connection terminal member is 0.3 to 3 μm, and the thickness at the soldering part of the connection terminal member is thicker than the thickness of the insertion / extraction part,
A plating film connection terminal member, wherein the thickness of the second plating layer is 0.05 to 0.2 μm.
(2) The difference (Td = Th−Ts) between the thickness (Ts) of the insertion / extraction portion of the first plating layer and the thickness (Th) of the soldering portion is set to 1.0 to 2.7 μm. (1) The connection terminal member according to (1).
(3) The connection terminal member according to (1) or (2), wherein a thickness of the insertion / extraction portion of the first plating layer is 1.5 μm or more.
(4) The connection terminal member according to any one of (1) to (3), wherein the thickness of the second plating layer is uniform in the insertion / extraction portion and the soldering portion.
( 5 ) The indium concentration of the second plating layer is decreased by the reflow process so as to be inclined from the plating surface side to the conductive substrate side. (1) to (4) The connection terminal member of any one of Claims .
( 6 ) The connection terminal according to any one of (1) to (5), wherein a base plating layer made of nickel or a nickel alloy is interposed between the first plating layer and the conductive base material. Element.
( 7 ) The connection terminal according to any one of (1) to ( 6 ), wherein a base plating layer made of copper or a copper alloy is interposed between the first plating layer and the conductive base material. Element.
( 8 ) The first plating layer is made of at least one selected from the group consisting of tin, tin-silver alloy, tin-bismuth alloy, tin-copper alloy, and tin-silver-copper alloy ( The connection terminal member according to any one of 1) to ( 7 ).
(9) A connection terminal comprising the connection terminal member according to any one of (1) to (8).
(10) A plating film obtained by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer. It is a material, Comprising: The thickness of the said 1st plating layer shall be 0.3-3 micrometers, and the thickness of the 2nd plating layer shall be 0.05-0.2 micrometers, The plating film material for connecting terminals characterized by the above-mentioned.
(11) The plating film material according to (10), wherein the first plating layer is provided with a predetermined thickness portion and a thinner portion.
(12) A multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate, and a second plating layer made of indium on the surface of the first plating layer, the first plating layer A multilayer plating material for connection terminals, wherein the plating layer has a thickness of 0.3 to 3 μm and the second plating layer has a thickness of 0.05 to 0.2 μm and is reflowed.
(13) The multilayer plating material according to (12), wherein the first plating layer is provided with a portion having a predetermined thickness and a portion thinner than the predetermined thickness. Forming a first plating layer made of tin or a tin alloy, forming a second plating layer made of indium on the surface of the first plating layer to obtain a multilayer plating material for a connection terminal member, and reflowing the multilayer plating material; In making a connection terminal member having an insertion / extraction part and a soldering part,
About the said 1st plating layer, the thickness in the said insertion / extraction part shall be 0.3-3 micrometers, and the thickness in the said soldering part is made thicker than the thickness of the said insertion / extraction part, On the other hand, the thickness of the said 2nd plating layer 0.05 to 0.2 μm is used for the multilayer plating material, and the multilayer plating material is reflowed to form a connection terminal member.

The above problems have been solved by the following means.
(1) A connection terminal obtained by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer A member,
For the first plating layer, the thickness at the insertion / extraction part of the connection terminal member is 0.3 to 3 μm, and the thickness at the soldering part of the connection terminal member is thicker than the thickness of the insertion / extraction part,
A plating film connection terminal member, wherein the thickness of the second plating layer is 0.05 to 0.2 μm.
(2) The difference (Td = Th−Ts) between the thickness (Ts) of the insertion / extraction portion of the first plating layer and the thickness (Th) of the soldering portion is set to 1.0 to 2.7 μm. (1) The connection terminal member according to (1).
(3) The connection terminal member according to (1) or (2), wherein a thickness of the insertion / extraction portion of the first plating layer is 1.5 μm or more.
(4) The connection terminal member according to any one of (1) to (3), wherein the thickness of the second plating layer is uniform in the insertion / extraction portion and the soldering portion.
(5) The indium concentration of the second plating layer is decreased in an inclined manner from the plating surface side to the conductive substrate side by the reflow treatment. (1) to (4) The connection terminal member of any one of Claims.
(6) The connection terminal according to any one of (1) to (5), wherein a base plating layer made of nickel or a nickel alloy is interposed between the first plating layer and the conductive substrate. Element.
(7) The connection terminal according to any one of (1) to (6), wherein a base plating layer made of copper or a copper alloy is interposed between the first plating layer and the conductive substrate. Element.
(8) The first plating layer is made of at least one selected from the group consisting of tin, tin-silver alloy, tin-bismuth alloy, tin-copper alloy, and tin-silver-copper alloy ( The connection terminal member according to any one of 1) to (7).
(9) A connection terminal comprising the connection terminal member according to any one of (1) to (8).
(10) A plating film obtained by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer. a timber, wherein the thickness of the first plating layer and 0.3 to 3 m, a thickness of the second plating layer a plating coat material for a connection pin which is 0.05 to 0.2 [mu] m and,
A plating film material characterized in that a portion having a predetermined thickness and a portion thinner than the predetermined thickness are provided for the first plating layer.
(11) When the connection terminal is used, a portion having a predetermined thickness of the first plating layer is a soldered portion, and a thinner portion is the insertion / extraction portion . Plating film material.
(12) A multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate, and a second plating layer made of indium on the surface of the first plating layer, the first plating layer the thickness of the plating layer is 0.3 to 3 m, and 0.05~0.2μm the thickness of the second plating layer, a multi-layer plating material for connecting terminals Ru used by reflowing, wherein the A multilayer plating material characterized in that a portion having a predetermined thickness and a portion thinner than the predetermined thickness are provided for one plating layer.
(13) When the connection terminal is used, a portion having a predetermined thickness of the first plating layer is used as the soldering portion, and a thinner portion is used as the insertion / extraction portion . Multi-layer plating material.
(14) A first plating layer made of tin or a tin alloy is formed on the outer side of the conductive substrate, and a second plating layer made of indium is formed on the surface of the first plating layer, so that multi-layer plating of the connection terminal member is performed. As a material, when reflowing the multilayer plating material to make a connection terminal member having an insertion / extraction portion and a soldering portion,
For the first plating layer, the thickness at the insertion / extraction portion is 0.3 to 3 μm, and the thickness at the soldering portion is larger than the thickness of the insertion / extraction portion, while the thickness of the second plating layer is A method for producing a plating film connection terminal member, characterized in that the multilayer plating material is 0.05 to 0.2 μm, and the multilayer plating material is reflowed to form a connection terminal member.

Claims (14)

A connection terminal member formed by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer. And
For the first plating layer, the thickness at the insertion / extraction part of the connection terminal member is 0.3 to 3 μm, and the thickness at the soldering part of the connection terminal member is thicker than the thickness of the insertion / extraction part,
A plating film connection terminal member, wherein the thickness of the second plating layer is 0.05 to 0.2 μm.   2. The connection terminal member according to claim 1, wherein the concentration of indium in the second plating layer is decreased in an inclined manner from the plating surface side to the conductive substrate side by the reflow treatment.   The connection terminal member according to claim 1, wherein a base plating layer made of nickel or a nickel alloy is interposed between the first plating layer and the conductive base material.   The connection terminal member according to claim 1, wherein a base plating layer made of copper or a copper alloy is interposed between the first plating layer and the conductive base material.   5. The connection terminal member according to claim 1, wherein a thickness of the second plating layer is made uniform in the insertion / extraction part and the soldering part.   The first plating layer is made of at least one selected from the group consisting of tin, tin-silver alloy, tin-bismuth alloy, tin-copper alloy, and tin-silver-copper alloy. The connection terminal member according to any one of 5.   The connection terminal member according to claim 1, wherein a thickness of the insertion / extraction portion of the first plating layer is 1.5 μm or more.   The difference (Td = Th−Ts) between the thickness (Ts) of the insertion / extraction portion of the first plating layer and the thickness (Th) of the soldering portion is 1.0 to 2.7 μm, The connection terminal member according to any one of claims 1 to 7.   A connection terminal comprising the connection terminal member according to claim 1.   A plating film material obtained by reflowing a multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer. Then, the thickness of the first plating layer is 0.3 to 3 μm, and the thickness of the second plating layer is 0.05 to 0.2 μm.   The plating film material according to claim 10, wherein the first plating layer is provided with a predetermined thickness portion and a thinner portion.   A multilayer plating material having a first plating layer made of tin or a tin alloy on the outside of a conductive substrate and a second plating layer made of indium on the surface of the first plating layer, A multilayer plating material for connection terminals, wherein the thickness is 0.3 to 3 μm, the thickness of the second plating layer is 0.05 to 0.2 μm, and reflow is used.   The multilayer plating material according to claim 12, wherein a portion having a predetermined thickness and a portion thinner than the predetermined thickness are provided for the first plating layer. Forming a first plating layer made of tin or a tin alloy on the outside of the conductive base material, forming a second plating layer made of indium on the surface of the first plating layer, and forming a multilayer plating material for the connection terminal member; In reflowing the multilayer plating material to form a connection terminal member having an insertion / extraction portion and a soldering portion,
Regarding the first plating layer, the thickness at the insertion / extraction portion is set to 0.3 to 3 μm, and the thickness at the soldering portion is made thicker than the thickness of the insertion / extraction portion, while the thickness of the second plating layer is set to A method for producing a plating film connection terminal member, characterized in that the multilayer plating material is 0.05 to 0.2 μm, and the multilayer plating material is reflowed to form a connection terminal member.