JP5477993B2 - Fitting type connecting part and method for manufacturing the same - Google Patents

Description

  The present invention relates to a fitting-type connecting component such as a connector terminal or a bus bar used mainly for electrical wiring of automobiles / consumer equipment, and a manufacturing method thereof, and particularly, to reduce friction and wear when inserting / removing a male terminal and a female terminal. The present invention relates to a fitting-type connecting component that requires a high-speed and a manufacturing method thereof.

  Patent Document 1 describes a conductive material for connection parts that has high electrical reliability (low contact resistance), a low coefficient of friction, and is suitable as a fitting connector terminal. In the invention of Patent Document 1, a copper alloy strip having a surface roughness larger than that of a normal copper alloy strip is used as a base material, and a Ni plating layer, a Cu plating layer, and a Sn plating layer are formed on the base material surface in this order, or Cu plating layer and Sn plating layer are formed in this order or only the Sn plating layer is formed, and the Sn plating layer is reflow-treated to form Cu-- from the Cu plating layer and the Sn plating layer, or from the copper alloy base material and the Sn plating layer. A part of the Cu-Sn alloy layer is exposed to the surface from between the Sn plating layer smoothed by the reflow process while forming the Sn alloy layer (Cu-Sn at the convex and concave portions formed on the surface of the base material) Part of the alloy layer is exposed).

  The conductive material for connecting parts formed after the reflow process in Patent Document 1 has a Cu—Sn alloy layer and a Sn layer, or a Ni layer, a Cu—Sn alloy layer, and a Sn layer in this order as a surface coating layer. Depending on the case, the Cu layer remains between the surface of the base material and the Cu—Sn alloy layer or between the Ni layer and the Cu—Sn alloy layer. In Patent Document 1, a Cu—Sn alloy layer and an Sn layer are formed on the outermost surface (the surface exposed area ratio of the Cu—Sn alloy layer is 3 to 75%), and the average thickness is 0.1 to 3.0 μm. The Cu content is specified to be 20 to 70 at%, the average thickness of the Sn layer is defined to be 0.2 to 5.0 μm, and the arithmetic average roughness Ra in at least one direction on the base material surface is 0.15 μm or more. It is described that the arithmetic average roughness Ra of the direction is preferably 4.0 μm or less, and the surface exposure interval of the Cu—Sn alloy layer is preferably 0.01 to 0.5 mm in at least one direction.

  Patent Document 2 describes a conductive material for connecting parts corresponding to the subordinate concept of Patent Document 1 and a method for manufacturing the same. The plating layer configuration and the coating layer configuration itself after the reflow treatment are the same as those in Patent Document 1. In the conductive material for connecting parts formed after the reflow process in Patent Document 2, a Cu—Sn alloy layer and an Sn layer are formed on the outermost surface (the surface exposed area ratio of the Cu—Sn alloy layer of the surface coating layer is 3 to 3). 75%), the average thickness of the Cu—Sn alloy layer is 0.2 to 3.0 μm, the Cu content is 20 to 70 at%, the average thickness of the Sn layer is 0.2 to 5.0 μm, The arithmetic average roughness Ra in at least one direction is 0.15 μm or more, the arithmetic average roughness Ra in all directions is defined as 3.0 μm or less, and the arithmetic average roughness Ra in at least one direction on the base material surface is 0.00. It is described that the arithmetic average roughness Ra in all directions is preferably 4.0 μm or less at 3 μm or more, and the surface exposure interval of the Cu—Sn alloy layer is preferably 0.01 to 0.5 mm in at least one direction. Yes.

  Patent Document 3 describes a conductive material for connecting parts that basically inherits the technical ideas of Patent Documents 1 and 2, and at the same time has improved solderability, and a manufacturing method thereof. In this invention, the plating layer structure and the coating layer structure itself after the reflow treatment are basically the same as those in Patent Documents 1 and 2, but the present invention is different from Patent Documents 1 and 2, and the Cu-Sn alloy layer. May be included (only the Sn layer on the outermost surface). In the conductive material for connecting parts formed after the reflow treatment in this application, the average thickness of the Ni layer of the surface coating layer is 3.0 μm or less, and the average thickness of the Cu—Sn alloy layer is 0.2 to 3 0.0 μm, diameter of the smallest inscribed circle [D1] of the Sn layer in the vertical section of the material is 0.2 μm or less, diameter [D2] of the largest inscribed circle is 1.2 to 20 μm, the outermost point of the material and Cu− When the height difference [Y] from the outermost point of the Sn alloy layer is specified to be 0.2 μm or less, and [D1] is 0 μm (a part of the Cu—Sn alloy layer is exposed and the outermost surface is a Cu—Sn alloy) The maximum inscribed circle diameter [D3] of the Cu—Sn alloy layer on the material surface is 150 μm or less and / or the maximum inscribed circle diameter [D4] of the Sn layer on the material surface is 300 μm or less. Is desirable.

  On the other hand, in Patent Documents 4 to 6, after a copper alloy sheet is subjected to punching, Sn plating is performed on the entire surface, so-called post plating is performed to form a Sn plating layer on the punched end face, and punching is performed. It is described that the solderability of terminals and the like is improved as compared with the case where the Sn plating is applied to the copper alloy sheet before (1).

Furthermore, Patent Documents 7 and 8 disclose that terminals that are subjected to post plating have high electrical reliability (low contact resistance), a low coefficient of friction at the fitting portion, and improved solderability at the soldering portion. Is described.
In the invention of Patent Document 7, the surface roughness is increased only at the fitting portion at the time of terminal molding, the Ni plating layer, the Cu plating layer, and the Sn plating layer in this order, or the Cu plating layer and the Sn plating layer in this order, or Only the Sn plating layer is formed, the Sn plating layer is reflowed, and the Cu-Sn alloy layer is formed from the Cu plating layer and the Sn plating layer, or from the copper alloy base material and the Sn plating layer, and smoothed by the reflow processing. A part of the Cu—Sn alloy layer is exposed on the surface from between the formed Sn plating layers (a part of the Cu—Sn alloy layer is exposed at the convex and concave portions formed on the surface of the base material). At this time, the entire plating thickness is the same. In the fitting part, since the Cu—Sn alloy layer and the Sn layer are formed on the outermost surface (the Cu—Sn alloy layer is exposed on the surface), there is a problem in solder wettability. Therefore, the Cu—Sn alloy layer is not exposed (only the Sn layer on the outermost surface), and the solder wettability is good.

  In the invention of Patent Literature 8, after a copper alloy material having a large surface roughness is punched to form a terminal material, the Ni plating layer, the Cu plating layer, and the Sn plating layer are arranged in this order, or the Cu plating layer and the Sn plating layer. The layers are formed in this order or only the Sn plating layer is formed, and the Sn plating layer is reflowed to form the Cu-Sn alloy layer from the Cu plating layer and the Sn plating layer, or from the copper alloy base material and the Sn plating layer. At the same time, a part of the Cu—Sn alloy layer is exposed on the surface from between the Sn plating layer smoothed by the reflow process (a part of the Cu—Sn alloy layer is formed on the uneven surface formed on the base material surface). Exposed). At this time, the Sn plating layer of the soldering portion is formed thick, so that the Cu—Sn alloy layer is not exposed on the surface in the soldering portion, and the solder wettability is good.

Japanese Patent No. 3926355 Japanese Patent No. 4024244 JP 2007-258156 A JP 2004-3000524 A JP 2005-105307 A JP 2005-183298 A JP 2008-269999 A JP 2008-274364 A

The conductive materials for connecting parts described in Patent Documents 1 to 3 and Patent Documents 7 and 8 use a surface roughened copper plate material as a base material, and have, for example, a Ni plating layer, a Cu plating layer, and a Sn plating layer on the surface. Are formed in this order, and the Sn plating layer is reflowed to form a Cu—Sn alloy coating layer from the Cu plating layer and the Sn plating layer, and the Cu—Sn alloy is smoothed between the Sn coating layers smoothed by the reflow processing. A part of the coating layer is exposed on the surface.
Conventionally, as an index of the exposed form of the Sn coating layer and the Cu—Sn coating layer, the exposed area ratio and average exposure interval of the Cu—Sn alloy coating layer (Patent Documents 1 and 2), and the maximum inscribed circle diameter of the Sn coating layer And a maximum circumscribed circle diameter (Patent Document 3).

On the other hand, the shape of individual Sn coating layers or Cu—Sn alloy coating layers has not received much attention so far. However, in order to cope with further miniaturization of the terminal, the plane is not limited to a slightly abstract index as described above, and the specific shape of each Sn coating layer or Cu—Sn alloy coating layer can be appropriately controlled. It is considered that a visual shape is required.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fitting-type connecting component that has a Sn coating layer or a Cu-Sn alloy coating layer having a proper and controllable plan view shape, and can cope with the miniaturization of terminals. And

The fitting-type connecting component according to the present invention is manufactured by post-plating and reflowing a copper plate material punched into a predetermined shape, and a Cu-Sn alloy coating layer and a Sn coating layer on the outermost surface on the contact side with the counterpart component The Sn coating layer is smoothed by a reflow process, and has the following features.
(1) The Sn coating layer includes a Sn coating layer group observed as a plurality of parallel lines, and the Cu-Sn alloy coating layer is adjacent to both sides of each Sn coating layer constituting the Sn coating layer group. Exists, and the maximum height roughness Rz of the surface in the component insertion direction is 10 μm or less, or
(2) The Sn coating layer includes one or more Sn coating layer groups that are observed as a plurality of parallel lines and one or more other Sn coating layer groups that are also observed as a plurality of parallel lines. Cu—Sn alloy coating layers exist adjacent to each other on both sides of each Sn coating layer constituting each Sn coating layer group, and the maximum height roughness Rz in the terminal insertion direction on the surface is 10 μm. The following.

In the fitting type connecting part, the width of the Sn coating layer belonging to each Sn coating layer group is 1 to 500 μm, and the interval between adjacent Sn coating layers among the Sn coating layers belonging to each Sn coating layer group is 1 to 2000 μm. It is desirable to be.
As described above, each Sn coating layer belonging to each Sn coating layer group refers to one observed as a plurality of parallel lines on the outermost surface on the contact (sliding) side with the counterpart component. The Sn coating layer does not necessarily have to be parallel lines in a mathematical sense. The present invention includes a case where individual Sn coating layers belonging to each Sn coating layer group are curved, wavy, or bent in substantially the same shape.

  In the fitting type connecting component, a Cu—Sn alloy coating layer and a Sn coating layer are formed on the outermost surface as a surface coating layer of a copper plate material (base material). As a specific form of the surface coating layer composed of the Cu—Sn alloy coating layer and the Sn coating layer, for example, as described in Patent Documents 1 to 3, the Cu—Sn alloy coating layer and the Sn coating layer are formed in this order. A form in which a part of the Cu—Sn alloy coating layer is exposed on the outermost surface from between the Sn coating layers smoothed by the reflow treatment is conceivable. In this case, the Cu—Sn alloy coating layer exposed on the outermost surface is measured as a peak of the roughness curve, and this peak is reflected in the size of the maximum height roughness Rz.

When the Cu—Sn alloy coating layer and the Sn coating layer are formed in this order, the average thickness of the Cu—Sn alloy coating layer is 0.1 to 3 μm, and the average thickness of the Sn coating layer is 0.2. It is desirable that it is -5.0 micrometers. The said average thickness of each coating layer is a numerical value equivalent to the thing of a prior art (the said patent documents 1-3).
A Ni coating layer may be formed between the surface of the copper plate (base material) and the Cu-Sn alloy coating layer as a part of the surface coating layer of the fitting-type connecting component, and the Ni coating A Cu coating layer may be further formed between the layer and the Cu—Sn alloy coating layer. Furthermore, a Cu coating layer may be formed between the surface of the copper plate material for connection parts and the Ni coating layer.
In the present invention, the Sn coating layer, the Ni coating layer, and the Cu coating layer include Sn alloy, Ni alloy, and Cu alloy in addition to Sn, Ni, and Cu metal, respectively.

According to the present invention, it is possible to provide a fitting-type connecting component having a low insertion force and excellent electrical reliability.
The planar view shapes of the Sn coating layer and the Cu—Sn alloy coating layer defined in the present invention are compatible with the miniaturization of the terminals, and the planar view is obtained by appropriately performing the surface roughening treatment of the copper plate material. The shape can be easily controlled.

It is a plane schematic diagram explaining the form of the surface coating layer of the fitting type connection component which concerns on this invention. It is another plane schematic diagram explaining the form of the surface coating layer of the fitting type connection component which concerns on this invention. It is a cross-sectional schematic diagram explaining the form of the surface coating layer of the fitting type connection component which concerns on this invention. It is a cross-sectional schematic diagram explaining the surface roughening process of the copper plate material used for the fitting type connection component which concerns on this invention. It is a top view of the copper plate material after the roughening process in an Example. No. of an Example. It is the surface SEM (composition image) and roughness curve of 1 test piece. It is a conceptual diagram of the jig | tool used for the friction coefficient evaluation test in an Example.

Hereinafter, the fitting-type connecting component according to the present invention will be specifically described.
The fitting-type connecting component of the present invention is manufactured by post-plating and reflowing a copper plate material punched into a predetermined shape, and a Cu-Sn alloy coating layer and Sn on the outermost surface in contact with the mating component. The coating layer is mixed and the Sn coating layer is smoothed by the reflow process. Regarding the surface coating layer composed of the Cu—Sn alloy coating layer and the Sn coating layer, more specifically, the Cu—Sn alloy coating layer and the Sn coating layer are formed in this order on the surface of the copper plate (base material). Part of the Cu—Sn alloy coating layer is exposed on the outermost surface from between the Sn coating layers smoothed by the reflow treatment. By exposing the hard Cu—Sn alloy coating layer on the outermost surface in contact (sliding) with the counterpart component, the terminal insertion force is reduced.
The Cu—Sn alloy coating layer exposed on the outermost surface is measured as a crest of a roughness curve based on JISB0601, and this crest is reflected in the magnitude of the maximum height roughness Rz.

In the fitting-type connecting component according to the present invention, the Sn coating layer and the Cu—Sn alloy coating layer present on the outermost surface on the contact side with the counterpart component take the following form (1) or (2).
(1) Both sides of each Sn coating layer that includes a Sn coating layer group observed as a plurality of parallel lines and constitutes the Sn coating layer group (this Sn coating layer may be referred to as a parallel Sn coating layer in particular) The Cu—Sn alloy coating layer is present adjacent to each other.
(2) One or two or more Sn coating layer groups observed as a plurality of parallel lines and another Sn coating layer group also observed as a plurality of parallel lines, and each Sn coating layer group intersects in a lattice pattern. A Cu—Sn alloy coating layer is present adjacent to both sides of each Sn coating layer constituting each Sn coating layer group (this Sn coating layer may be referred to as a parallel Sn coating layer in particular).

The forms (1) and (2) of the parallel Sn coating layer and the Cu—Sn alloy coating layer will be described with reference to the schematic diagrams of FIGS. 1 and 2 are schematic plan views showing a part of the outermost surface of the fitting type connecting part extracted in a substantially square shape.
First, FIGS. 1A and 1B show a typical example of the form (1). In the example shown in FIG. 1A, a plurality of parallel Sn coating layers 1a to 1d having a predetermined width (sometimes collectively referred to as parallel Sn coating layers 1) are formed in parallel lines at substantially equal intervals, and each parallel line is formed. The Cu—Sn alloy coating layer 2 is adjacent to both sides of the Sn coating layers 1a to 1d. The Cu—Sn alloy coating layer 2 also has a predetermined width, and is formed in parallel lines at substantially equal intervals. The plurality of parallel Sn coating layers 1a to 1d formed in a parallel line form the Sn coating layer group X referred to in the present invention.

In the example shown in FIG. 1B, a plurality of parallel Sn coating layers 1a to 1d having a predetermined width are formed in parallel lines at substantially equal intervals, and Cu—Sn alloy coating layers 2 are adjacent to both sides thereof. To do. The Cu—Sn alloy coating layer 2 also has a predetermined width and is formed in parallel lines at substantially equal intervals, but the Sn coating layer 3 exists in an island shape in the Cu—Sn alloy coating layer 2. Thus, it is different from the example of FIG. The plurality of parallel Sn coating layers 1 formed in parallel lines form the Sn coating layer group X referred to in the present invention.
In addition, when Sn coating layer 3 which exists in island shape in FIG.1 (b) is continuous, and Cu-Sn alloy coating layer 2 is parted, or Cu-Sn alloy coating layer in Sn coating layer 3 further. Various other forms may occur, such as when the islands are small and in the form of islands.

  2A and 2B show typical examples of the form (2). In the example shown in FIG. 2A, a plurality of parallel Sn coating layers 1a to 1d having a predetermined width are formed in parallel lines at substantially equal intervals, and intersecting at right angles to the plurality of parallel Sn coating layers 1a to 1d Parallel Sn coating layers 4a to 4d (sometimes collectively referred to as parallel Sn coating layer 4) are formed in parallel lines at substantially equal intervals. The plurality of parallel Sn coating layers 1a to 1d formed in parallel lines constitutes the Sn coating layer group X referred to in the present invention, and the plurality of parallel Sn coating layers 4a to 4d also formed in parallel lines, The Sn coating layer group Y referred to in the present invention is configured. The two Sn coating layer groups X and Y intersect in a lattice pattern, and the Cu—Sn alloy coating layer 2 exists in an area surrounded by each lattice. Also in this case, it can be said that the Cu—Sn alloy coating layer 2 exists adjacent to both sides of each parallel Sn coating layer 1, 4.

In the example shown in FIG. 2B, a plurality of parallel Sn coating layers 1a to 1d having a predetermined width are formed in parallel lines at substantially equal intervals, and intersecting at right angles to the plurality of parallel Sn coating layers 1a to 1d having a predetermined width. Parallel Sn coating layers 4a to 4d are formed in parallel lines at substantially equal intervals. The plurality of parallel Sn coating layers 1a to 1d formed in parallel lines constitutes the Sn coating layer group X referred to in the present invention, and the plurality of parallel Sn coating layers 4a to 4d also formed in parallel lines, The Sn coating layer group Y referred to in the present invention is configured. The two Sn coating layer groups X and Y intersect in a lattice pattern, and the Cu—Sn alloy coating layer 2 exists in an area surrounded by each lattice. In this example, the Sn coating layer 3 exists in an island shape in the Cu—Sn alloy coating layer 2, and this is different from the example of FIG. Also in this case, it can be said that the Cu—Sn alloy coating layer 2 exists adjacent to both sides of each parallel Sn coating layer 1, 4.
In FIG. 2B, various other forms may occur, for example, when the Cu—Sn alloy coating layer is present in an island shape in the Sn coating layer 3 existing in an island shape.

1 and 2, the Cu—Sn alloy coating layer 2 exposed on the surface is a parallel Sn coating layer 1 (also Sn coating layer 3 and parallel Sn coating layer 4) smoothed by reflow treatment. It protrudes in the height direction from the level of. The cross-sectional form of such both coating layers is demonstrated with reference to the cross-sectional schematic diagram shown in FIG.
In FIG. 3, the copper plate material (base material) 5 has relatively deep recesses 6 formed at substantially equal intervals, convex portions 7 are formed on both sides of the recess 6, and adjacent convex portions 7 that do not sandwich the recess 6. Between 7 is relatively flat. Such a surface structure is called a plateau structure. The recess 6 is observed as a plurality of parallel lines on the surface of the copper plate material 5.

FIG. 3A corresponds to FIG. 1A (or FIG. 2A), and the Cu—Sn alloy coating layer 2 is formed on the entire surface of the copper plate material 5, and Cu—Sn is formed in the recess 6. A parallel Sn coating layer 1 is formed on the alloy coating layer 2. The parallel Sn coating layers 1 formed in the recesses 6 are parallel Sn coating layers 1a to 1d (or parallel Sn coating layers 4a to 4d) observed in parallel lines in FIG. 1 (a) or FIG. 2 (a). It corresponds to.
FIG. 3B corresponds to FIG. 1B (or FIG. 2B), and the Cu—Sn alloy coating layer 2 is formed on the entire surface of the copper plate material 5, and Cu—Sn is formed in the recess 6. A parallel Sn coating layer 1 is formed on the alloy coating layer 2. The Sn coating layer 3 is formed on the Cu—Sn alloy coating layer 2 also in the plateau portion. The parallel Sn coating layers 1 formed in the recesses 6 are parallel Sn coating layers 1a to 1d (or parallel Sn coating layers 4a to 4d) observed in parallel lines in FIG. 1B or 2B. The Sn coating layer 3 formed on the plateau portion corresponds to the Sn coating layer 3 observed in an island shape in FIG. 1B or FIG.

Here, an example of the means for forming the surface coating layer composed of the Cu—Sn alloy coating layer 2 and the parallel Sn coating layer 1 (and the parallel Sn coating layer 4) will be specifically described.
After punching into the part shape, before punching or simultaneously with punching, the copper plate material 5 is subjected to surface roughening treatment by press working. In this surface roughening treatment, as shown in FIG. 4 (a), a mold 8 in which fine irregularities are formed on a pressing surface at a substantially constant pitch is set in a press machine, and the mold 8 is used to This is done by pressing the surface. By this pressing, the convex portion (blade edge) of the pressing surface of the mold 8 is pushed into the surface of the copper plate material 5, and the concave portion 6 is transferred to the surface of the copper plate material 5 in the form of parallel lines, and is simultaneously pushed out of the concave portion 6. The raised material swells on both sides of the concave portion 6, and the convex portion 7 is inevitably formed. The surface of the copper plate material between the adjacent convex portions 7 and 7 that do not sandwich the concave portion 6 is kept relatively flat (plateau) as it is finish-rolled.

Subsequently, for example, Cu plating and Sn plating are performed on the surface of the copper plate material 5 punched out into a component shape, and reflow treatment is further performed. By this reflow treatment, a Cu—Sn alloy coating layer is formed from Cu of the Cu plating layer and Sn of the Sn plating layer, and molten Sn flows into the recesses 6 and the like. As a result, as shown in FIG. 3A, the smoothed parallel Sn coating layer 1 is formed on the Cu—Sn alloy coating layer 2, and a part of the Cu—Sn alloy coating layer 2 is a parallel Sn coating layer. 1 is exposed adjacent to the parallel Sn coating layer 1. At this time, a part of the Cu plating layer may remain under the Cu—Sn alloy coating layer 2.
In the present invention, each layer constituting the surface coating layer after the reflow treatment is expressed as “coating layer”, and each layer constituting the surface plating layer before the reflow processing is expressed as “plating layer”.
If the amount of Sn remaining after the reflow treatment is relatively large, the Sn coating layer 3 is formed on the plateau portion on the surface of the copper alloy plate (see FIGS. 1B, 2B, and 3B), Or the coating area of the said Sn coating layer 3 increases. As shown in FIG. 3B, the Sn coating layer 3 is thinner than the parallel Sn coating layer 1.

  The parallel Sn coating layer 1 constituting the Sn coating layer group X and the parallel Sn coating layer 4 constituting the Sn coating layer group Y are adjacent to each other in widths a and b (see FIGS. 1 and 2) of 1 to 500 μm. The distances c and d (see FIGS. 1 and 2) between the parallel Sn coating layers are set to 1 to 2000 μm. Note that the width of the parallel Sn coating layer and the interval between adjacent parallel Sn coating layers are set as described above so that the parallel Sn coating layer and the Cu-Sn alloy coating layer are on the outermost surface as long as they are within this range. This is because it is possible to ensure both reduction in insertion force and electrical reliability due to a low friction coefficient when mixed appropriately.

More specifically, the width of the parallel Sn coating layer is set to 1 μm or more because it is difficult to form a parallel Sn coating layer with a narrower width on the surface roughening treatment of the copper plate material. . On the other hand, if the width of the parallel Sn coating layer becomes too large, the contact portion of the mating terminal enters the parallel Sn coating layer and the insertion force increases, so the width of the parallel Sn coating layer is set to 500 μm or less. Considering the recent miniaturization of terminals, the width of the parallel Sn coating layer is desirably 200 μm or less, and more desirably 50 μm or less.
The reason why the interval between adjacent parallel Sn coating layers is set to 1 μm or more is that the surface roughening treatment of the copper plate material is difficult. On the other hand, if the distance between adjacent parallel Sn coating layers becomes too large, the contact area between the counterpart terminal and the Cu—Sn alloy coating layer becomes too large or too small depending on the initial thickness of the Sn plating layer. In this case, in any case, an increase in insertion force (decrease in low insertion force effect) is caused. Therefore, the interval between adjacent parallel Sn coating layers is set to 2000 μm or less. Considering the recent miniaturization of terminals, the width of the parallel Sn coating layer is desirably 1000 μm or less, and more desirably 250 μm or less. Although it is desirable that the width of the parallel Sn coating layer and the interval between the adjacent parallel Sn coating layers are substantially constant, it is not essential.

As shown in FIG. 3, the Cu—Sn alloy coating layer 2 exposed on the outermost surface protrudes in the height direction from the level of the parallel Sn coating layer 1 and the Sn coating layer 3. For this reason, for example, when the surface roughness is measured in the terminal insertion direction (indicated by white arrows in FIGS. 1 and 2), it is measured as a peak of a roughness curve based on JISB0601.
In the present invention, the maximum height roughness Rz in the component (terminal) insertion direction is defined as 10 μm or less (including 0 μm). When this maximum height roughness Rz is large, the surface area of the Cu—Sn alloy coating layer exposed on the outermost surface is increased, the corrosion resistance of the component surface is reduced, the amount of oxides is increased, and the contact resistance is likely to increase. It becomes difficult to maintain the reliability of the machine. Further, when the concave portion 6 is formed wide and deep in the copper plate material 5 in the surface roughening treatment of the copper plate material, the maximum height roughness Rz increases, but this tends to be accompanied by deformation of the copper plate material 5. Therefore, the maximum height roughness Rz is set to 10 μm or less, and preferably more than 0 (extruded somewhat) to 5 μm or less.

In the example of FIG. 2, the two parallel Sn coating layer groups X and Y intersect each other at right angles, but this intersection angle can be set as appropriate. When two parallel Sn coating layer groups X and Y are crossed, the corner of the Cu-Sn alloy coating layer rises higher (the corner where the two concave portions intersect in the surface roughening process rises), and low insertion Power effect is improved. However, if the width of the parallel Sn coating layer and the interval between adjacent parallel Sn coating layers are the same, the smaller the crossing angle is, the wider the rising interval is, and the low insertion force effect is reduced. For this reason, this crossing angle is desirably 10 ° to 90 °.
It is also included in the present invention that three or more Sn coating layer groups intersect in a lattice pattern. Also in this case, the parallel Sn coating layers constituting each Sn coating layer group have a width of 1 to 500 μm, and the interval between adjacent parallel Sn coating layers included in the same Sn coating layer group is set to 1 to 2000 μm. Similarly, the crossing angle of each Sn coating layer group is preferably 10 to 90 °.

  In the fitting connection component according to the present invention, the angle formed by the component (terminal) insertion direction and the length direction of the Sn coating layer group may be appropriately set in the range of 0 ° to 90 °. When there is one Sn coating layer group, the angle is preferably more than 0 ° to 90 °, and the larger the angle, the more desirably 20 ° to 90 °, and further desirably 90 °. When there are a plurality of Sn coating layer groups, at least one of the Sn coating layer groups is set such that the angle with the insertion direction is as described above.

Of the surface coating layer formed on the surface of the copper plate material, the Cu-Sn alloy coating layer is composed of one or both of Cu ₆ Sn ₅ and Cu ₃ Sn, and the average thickness is 0.1 to 3.0 μm. . This is a numerical value equivalent to that of the prior art (Patent Documents 1 and 2). When the average thickness of the Cu—Sn alloy coating layer is less than 0.1 μm, the corrosion resistance of the material surface is reduced, the amount of oxide is increased, the contact resistance is likely to increase, and it is difficult to maintain electrical reliability. . On the other hand, if it exceeds 3.0 μm, it is disadvantageous in terms of cost and the productivity is also deteriorated. Therefore, the average thickness of the Cu—Sn alloy coating layer is 0.1 to 3.0 μm, and preferably 0.2 to 1.0 μm.

  The Sn coating layer is made of Sn metal or Sn alloy. In the case of Sn alloy, Cu, Ag, Ni, Bi, Zn etc. are mentioned as an alloy element, and it is desirable that these elements are 10 mass% or less. The average thickness of the Sn coating layer is 0.2 to 5.0 μm. This is a numerical value equivalent to that of the prior art (Patent Documents 1 and 2). If the average thickness of the Sn coating layer is less than 0.2 μm, the amount of Cu oxide on the material surface increases due to thermal diffusion such as high-temperature oxidation, and the contact resistance tends to increase and the corrosion resistance also deteriorates. It becomes difficult to maintain. On the other hand, if it exceeds 5.0 μm, it is disadvantageous in terms of cost, and productivity is also deteriorated. Therefore, the average thickness of the Sn coating layer is 0.2 to 5.0 μm, and preferably 0.5 to 3.0 μm.

A Ni coating layer may be formed between the surface of the copper plate material and the Cu—Sn alloy coating layer as a part of the surface coating layer of the fitting type connecting component, and the Ni coating layer and the Cu— A Cu coating layer may be further formed between the Sn alloy coating layers. Furthermore, a Cu coating layer may be formed between the surface of the copper plate material for connection parts and the Ni coating layer. These coating layers are all formed by plating. As described above, the Cu coating layer between the Ni coating layer and the Cu-Sn alloy coating layer is coated with Cu-Sn alloy after the reflow treatment. This is a Cu plating layer remaining under the layer.
The Ni coating layer is made of metal Ni or Ni alloy. In the case of Ni alloy, Cu, P, Co, etc. are mentioned as an alloy element, Cu is 40 mass% or less, P and Co are 10 mass% or less. The average thickness of the Ni coating layer is preferably 0.1 to 10 μm. The Cu coating layer is made of metal Cu or Cu alloy. In the case of a Cu alloy, examples of alloy elements include Sn and Zn. Sn is preferably less than 50% by mass, and other elements are preferably 5% by mass or less. The average thickness of the Cu coating layer is desirably 3.0 μm or less.

Next, a supplementary description will be given of the method for manufacturing the fitting type connecting component.
As surface roughening treatment methods, Patent Documents 1 to 3 include physical methods such as ion etching, chemical methods such as etching and electropolishing, and rolling (using a work roll roughened by polishing or shot blasting). Mechanical methods such as polishing, shot blasting, etc. are disclosed. However, the Sn coating layer group observed as a plurality of parallel lines as described above and a Cu—Sn alloy coating layer adjacent to both sides thereof cannot be formed by such a method.
On the other hand, Patent Documents 7 and 8 describe a technique for roughening the surface of a copper plate material during terminal shape processing. That is, a copper plate material is punched to form a copper plate material in which terminal materials are connected in a chain in the length direction via a strip-shaped connecting portion, and at the same time as the punching process or before or after the punching process, The plate material is pressed to increase the surface roughness of the terminal material plate surface (copper plate material surface). However, Patent Documents 7 and 8 do not describe specific means for pressing.

The Cu—Sn alloy coating layer is exposed after the reflow treatment at the convex portion of the surface of the copper plate material subjected to the surface roughening treatment (artificially formed irregularities). Therefore, the exposed form of the Cu—Sn alloy coating layer or the Sn coating layer reflects the form of irregularities formed on the surface of the copper plate material in the surface roughening treatment.
In the present invention, as described above with reference to FIG. 4, as the surface roughening treatment, a mold in which fine irregularities are formed in parallel lines on the pressing surface is set in a press machine. The method of pressing the surface of a copper plate material and driving a convex part (blade edge) into the copper plate material surface is applicable. With this method, it is possible to realize the exposed form of the Cu—Sn alloy coating layer or the Sn coating layer defined in the present invention, and the width of the Sn coating layer and the interval between the Sn coating layers can be freely controlled. .
In addition, there are electrical discharge machining, grinding machining, laser machining, and the like as a method for giving fine unevenness to the pressing surface of the mold 1 and can be arbitrarily selected depending on required dimensional accuracy and machining shape. The shape of the protrusions and the formation pitch need not be constant.

After punching into the part shape and surface roughening treatment, so-called post plating is performed on the copper plate material. The area | region which performs a surface roughening process and post-plating with respect to a copper plate material may extend to the single side | surface or both surfaces of a copper plate material, and may occupy only a part of single side | surface or both surfaces. What is necessary is just to go to the surface used as a sliding surface at the time of fitting with the other party member at least of a copper plate material.
Post-plating can be manufactured by performing reflow processing after forming a Cu plating layer and a Sn plating layer in this order after performing Ni plating as required. Further, if necessary, a Cu plating layer can be formed under the Ni plating layer to improve the adhesion of the Ni plating. Alternatively, only the Sn plating layer may be formed directly on the copper plate material surface.

  When the reflow treatment is applied to the post-plated copper plate material, Cu and Sn of the Cu plating layer and the Sn plating layer are mutually diffused to form a Cu-Sn alloy coating layer, and at that time, the Sn plating layer remains, and Cu The plating layer can be both extinguished or partially retained. When a part of the Cu plating layer remains, a Cu coating layer is formed between the copper plate material surface (the Ni coating layer surface when the Ni plating layer is formed) and the Cu-Sn alloy coating layer. When the Ni plating layer is not formed, depending on the thickness of the Cu plating layer, Cu may be supplied also from the copper plate material (base material). When only the Sn plating layer is directly formed on the surface of the copper plate material, Cu in the copper plate material (base material) and Sn in the Sn plating layer mutually diffuse to form a Cu—Sn alloy coating layer.

The average thickness of the Cu plating layer is preferably 0.1 to 1.5 μm, the average thickness of the Sn plating layer is preferably 0.3 to 8.0 μm, and the average thickness of the Ni plating layer is preferably 0.1 to 10 μm.
In addition, in this invention, Cu plating layer, Sn plating layer, and Ni plating layer contain Cu alloy, Sn alloy, and Ni alloy other than Cu, Sn, and Ni metal, respectively. When the Cu plating layer, the Sn plating layer, and the Ni plating layer are a Cu alloy, a Sn alloy, and a Ni alloy, the alloy element of each alloy may be the same as each alloy of the Cu coating layer, the Sn coating layer, and the Ni coating layer.

  The following examples will focus on the essential points and more specifically describe the present invention, but the present invention is not limited to these examples.

[Production of copper plate material (plating base material)]
In this example, Cu contains 1.8 mass% Ni, 0.40 mass% Si, 1.1 mass% Zn, 0.10 mass% Sn, Vickers hardness 180, thickness A copper alloy strip having a thickness of 0.25 mm was manufactured.
A test piece of 100 mm × 40 mm (longitudinal direction of rolling × right angle direction) is cut out from the copper alloy strip, and predetermined on the pressing surface at a predetermined position (position after the pin terminal forming process) in the progressive die for forming the pin terminal. The parts with irregularities were attached, and a pin terminal shape of 1 mmw × 22 mmL was molded at a pitch of 5 mm, and at the same time, a surface roughening treatment was performed in the range of 1 mmw × 10 mmL of each pin terminal. FIG. 5 shows a schematic view of the copper plate material after the forming process and the surface roughening treatment. In FIG. 5, 11 is a copper plate material, 12 is a pin terminal part, and the range of a double-headed arrow is a surface roughened portion. Various surface forms can be obtained by using parts with different concavo-convex shapes or performing multiple hits.

Subsequently, no. The copper plate materials 1 to 16 were subjected to Ni plating (partially not applied), then subjected to Cu plating and Sn plating, and then subjected to reflow treatment at 280 ° C. for 10 seconds to obtain test pieces.
No. A surface SEM (composition image) of No. 1 is shown in FIG. In the figure, the white part is the Sn coating layer, and the black part is the Cu—Sn alloy coating layer. The Sn coating layer includes two Sn coating layer groups that are each observed as a plurality of parallel lines. One Sn coating layer group and the other Sn coating layer group intersect at an angle of 90 °, and the lattice layer as a whole. It has a shape. In this example, after the surface roughening treatment, fine grooves (valleys) observed as a plurality of parallel lines are formed to intersect at an angle of 90 ° on the surface of the pin terminal before plating, and these grooves are entirely formed. As a grid.

  Table 1 shows the surface morphology of each test piece and the average thickness of each coating layer. In Table 1, the straight line X refers to the Sn coating layer constituting one Sn coating layer group, and the straight line Y refers to the Sn coating layer constituting the other Sn coating layer group, and only one Sn coating layer group exists. If not, the straight line Y column is left blank. Each parameter indicating the surface form of each test piece and the method for measuring the average thickness of each coating layer are as follows.

[Maximum roughness Rz]
It measured based on JISB0601: 2001 using the contact-type roughness meter (the Tokyo Seimitsu make; Surfcom 1400). The surface roughness measurement conditions were as follows: the cutoff value was 0.8 mm, the reference length was 0.8 mm, the evaluation length was 4.0 mm, the measurement speed was 0.3 mm / s, and the contact needle tip radius was 5 μmR. The maximum height roughness Rz was obtained from each of the obtained roughness curves, and the maximum value was taken as the maximum height roughness Rz of the test piece. The maximum height roughness Rz was almost the same value at any measurement location. In FIG. An example of the roughness curve measured by 1 is shown.

[Sn layer width, etc.]
The surface of the test piece was observed using an operation electron microscope, and the width of the Sn coating layer (X, Y) and the distance between the straight lines X, Y were measured from the composition image. The crossing angle of X and Y, and the crossing angle of X and the insertion direction were set at the stage of surface roughening treatment.
[Coating layer thickness]
The test piece was cut in a cross section perpendicular to the Sn coating layer observed in parallel lines, the central part of the cross section was observed using a scanning electron microscope, and the composition image was subjected to image analysis processing to obtain a Ni coating layer. The average thickness of the Cu—Sn alloy coating layer and the Sn coating layer was calculated. In all cases, the Cu coating layer disappeared.

  Subsequently, the obtained test piece was subjected to a friction coefficient evaluation test and a contact resistance evaluation test after being left at a high temperature in the following manner. The results are shown in Table 2. In Table 2, the emboss 1.5 column of the friction coefficient is the friction coefficient when the inner diameter of the female test piece is 1.5 mm, and the emboss 1.0 column is the inner diameter of the female test piece hemisphere is 1.0 mm. The coefficient of friction is shown. The column of the tongue piece in Table 2 describes the coefficient of friction when the female test piece is a curved tongue piece having a width of 10 mm (curvature radius of 2 mm).

[Friction coefficient evaluation test]
The shape of the indented portion of the electrical contact in the fitting type connecting part was simulated and evaluated using an apparatus as shown in FIG. First, a pin terminal-shaped male test piece 14 cut out from each test material (No. 1 to 16) is fixed to a horizontal base 15, and a copper plate material that has not been subjected to surface roughening treatment is plated thereon ( Cu: 0.15 μm, Sn: 1.0 μm, reflow treatment) A hemispherical material cut out from the material (with an inner diameter of φ1.5 mm and φ1.0 mm) or a female test piece 16 formed on a tongue piece and covered The layers were brought into contact. Subsequently, a 3.0 N load (weight 17) is applied to the female test piece 6 to hold down the male test piece 14, and the male test piece 14 is attached using a horizontal load measuring device (Aiko Engineering Co., Ltd .; Model-2152). The test piece was pulled in the horizontal direction in the terminal insertion direction (the sliding speed was 80 mm / min), and the maximum frictional force F (unit: N) up to a sliding distance of 5 mm was measured. The coefficient of friction was determined by the following formula (1). In addition, 18 is a load cell and the arrow is a sliding direction.
Friction coefficient = F / 3.0 (1)

[Evaluation test for contact resistance after standing at high temperature]
Each test material was subjected to a heat treatment at 160 ° C. for 500 hours in the air, and then contact resistance was measured by a four-terminal method under an open voltage of 20 mV, a current of 10 mA, and no sliding. A sample having a contact resistance of less than 1.0 mΩ after heating at 160 ° C. for 500 hours was evaluated as good (◯), and a sample having a contact resistance of 1.0 mΩ or more was evaluated as inferior in heat resistance (×).

  As shown in Table 2, no. 1 to 13 satisfy the requirements defined in the present invention regarding the width and interval of the Sn coating layer and the maximum height roughness Rz, and at least when the counterpart material is a tongue piece, the friction coefficient is a low value of less than 0.4. Is shown. In particular, each parameter is within a desired range, that is, the maximum height roughness Rz is 0.1 to 5 μm, the width of the Sn coating layer (straight line X, Y) is 50 μm or less, and the interval between adjacent Sn coating layers (adjacent straight line X , X, and the distance between the straight lines Y, Y) are 250 μm or less, the coefficient of friction is as low as less than 0.4 even at 1.0 mm emboss.

  On the other hand, no. No. 14 has a maximum height roughness Rz that is too high, so that the contact resistance after heating is high. No. 15 has a high friction coefficient because the width of the Sn coating layer is too large. No. 16 has a high friction coefficient because the interval between the Sn coating layers (the interval between adjacent straight lines X and X, the interval between straight lines Y and Y) is too large.

1,1a-1d Parallel Sn coating layer
2 Cu-Sn alloy coating layer
3 Sn coating layer 4, 4a-4d Parallel Sn coating layer
5 Copper plate material 6 Concave portion 7 Convex portion 8 Mold 11 Copper plate material 12 Pin terminal portion

Claims (11)

It is manufactured by post-plating and reflow treatment on a copper plate material that has been punched into a predetermined shape. A Cu-Sn alloy coating layer and a Sn coating layer are mixed on the outermost surface on the contact side with the mating terminal, and the Sn coating layer is reflowed. In the fitting type connecting part smoothed by the above, the Sn coating layer is composed of one Sn coating layer group observed as a plurality of parallel lines and another Sn coating layer group also observed as a plurality of parallel lines. 2 or more, each Sn coating layer group intersects in a lattice pattern, Cu-Sn alloy coating layers are adjacent to both sides of each Sn coating layer constituting each Sn coating layer group, and the maximum in the component insertion direction A fitting-type connecting part having a height roughness Rz of 10 μm or less. Claims width of Sn coating layers belonging to the Sn coating layer group 1 to 500 [mu] m, distance Sn coating layers adjacent to each other among the Sn coating layer belonging to the same Sn coating layer group is characterized in that it is a 1~2000μm 1 is a fitting type connecting component described in 1 . The copper plate is surface roughening treatment is performed before the post-plating, the recess being observed as a plurality of parallel lines on the surface according to claim 1 or 2, characterized in that it is formed by press working Fitting connection parts. It is manufactured by post-plating and reflow treatment on a copper plate that has been punched into a predetermined shape. The Cu-Sn alloy coating layer and the Sn coating layer are mixed on the outermost surface on the contact side with the counterpart component, and the Sn coating layer is reflowed. In the fitting type connecting part smoothed by the above, the copper plate material is subjected to surface roughening before post-plating, and concave portions observed as a plurality of parallel lines are formed by pressing on the surface, The Sn coating layer includes a Sn coating layer group observed as a plurality of parallel lines, and the Cu-Sn alloy coating layer exists adjacent to both sides of each Sn coating layer constituting the Sn coating layer group, A fitting type connecting part, wherein the maximum height roughness Rz in the part inserting direction is 10 μm or less. Claims width of Sn coating layers belonging to the Sn coating layer group 1 to 500 [mu] m, distance Sn coating layers adjacent to each other among the Sn coating layer group belonging Sn coating layer is characterized in that it is a 1~2000μm 4 is a fitting type connecting part described in item 4 ; The Cu-Sn alloy coating layer and the Sn coating layer are formed in this order as a surface plating layer on the surface of the copper plate material, and a part of the Cu-Sn alloy coating layer is exposed on the outermost surface. The fitting type connection component according to any one of claims 1 to 5. 7. The fitting according to claim 6, wherein an average thickness of the Cu—Sn alloy coating layer is 0.1 to 3 μm, and an average thickness of the Sn coating layer is 0.2 to 5.0 μm. Mold connection parts. The fitting type connecting component according to claim 6 or 7 , wherein a Ni coating layer is provided between the surface of the copper plate material and the Cu-Sn alloy coating layer. The fitting type connecting component according to claim 8, further comprising a Cu coating layer between the Ni coating layer and the Cu-Sn alloy coating layer. The fitting type connecting component according to claim 8 or 9, further comprising a Cu coating layer between a surface of the copper plate material and the Ni coating layer. Simultaneously with or before and after the copper plate material is punched, the surface of the copper plate material is subjected to a surface roughening treatment by pressing to form a plurality of concave portions that are observed as parallel lines, followed by a surface roughening treatment. The method for manufacturing a fitting-type connecting component according to any one of claims 1 to 10, wherein the surface of the copper plate material is post-plated and further subjected to reflow treatment.